Equity [Abstract] Treasury Stock Activity Stockholders' Equity Note Disclosure [Text Block] Debt Disclosure [Abstract] Interest expense Interest Expense, Debt Capitalized interest Interest Costs Capitalized Adjustment Interest expense Interest Expense Interest income Investment Income, Interest Interest expense, net Interest Income (Expense), Nonoperating, Net Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Schedule of the Changes in the Carrying Value of Goodwill by Reportable Segment Schedule of Goodwill [Table Text Block] Schedule of Gross Carrying Amount and Accumulated Amortization for Each Major Class of Intangible Asset Schedule of Finite-Lived Intangible Assets [Table Text Block] Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common Stock Common Stock [Member] Class B common stock Common Class B [Member] Statement [Line Items] Statement [Line Items] Dividends paid per share (USD per share) Common Stock, Dividends, Per Share, Cash Paid Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Corporate Debt Securities Debt Security, Corporate, US [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 2.90% Notes due 2020 Notes 2.90% Due 2020 [Domain] Notes 2.90% Due 2020 4.125% Notes due 2020 Notes 4.125% Due 2020 [Member] Notes 4.125% Due 2020 [Member] 3.10% Notes due 2021 Notes 3.10% Due 2021 [Domain] Notes 3.10% Due 2021 8.8% Debentures due 2021 Debentures 8.8% Due 2021 [Member] Debentures 8.8% Due 2021 [Member] 3.375% Notes due 2023 Notes 3.375% Due 2023 [Domain] Notes 3.375% Due 2023 2.625% Notes due 2023 Notes 2.625% Due 2023 [Member] Notes 2.625% Due 2023 [Member] 3.20% Notes due 2025 Notes 3.20% Due 2025 [Member] Notes 3.20% Due 2025 [Member] 2.30% Notes due 2026 Notes 2.30% Due 2026 [Member] Notes 2.30% Due 2026 [Member] 7.2% Debentures due 2027 Debentures 7.2% Due 2027 [Member] Debentures 7.2% Due 2027 [Member] 3.375% Notes due 2046 Notes 3.375% Due 2046 [Member] Notes 3.375% Due 2046 [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Total long-term debt Long-term Debt Finance Lease, Liability Finance Lease, Liability Net impact of interest rate swaps, debt issuance costs and unamortized debt discounts Debt Instrument, Impact of Derivatives, Unamortized Discount (Premium), and Debt Issuance Costs, Net Debt Instrument, Impact of Derivatives, Unamortized Discount (Premium), and Debt Issuance Costs, Net Current portion of long-term debt Long-term Debt and Lease Obligation, Current Long-term debt Long-term Debt and Lease Obligation Derivative Instruments and Hedging Activities Disclosure [Abstract] Schedule of the Classification of Derivative Assets and Liabilities within the Consolidated Balance Sheets Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Schedule of the Effect of Derivative Instruments on the Consolidated Statements of Income Derivative Instruments, Gain (Loss) [Table Text Block] Statement of Financial Position [Abstract] ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Accounts receivable—trade, net Accounts Receivable, after Allowance for Credit Loss, Current Inventories Inventory, Net Prepaid expenses and other Prepaid Expense and Other Assets, Current Total current assets Assets, Current Property, plant and equipment, net Property, Plant and Equipment, Net Goodwill Goodwill Other intangibles Intangible Assets, Net (Excluding Goodwill) Other assets Other Assets, Noncurrent Deferred income taxes Deferred Income Tax Assets, Net Total assets Assets LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued liabilities Accrued Liabilities, Current Accrued income taxes Accrued Income Taxes, Current Short-term debt Short-term Debt Total current liabilities Liabilities, Current Other long-term liabilities Other Liabilities, Noncurrent Deferred income taxes Deferred Income Tax Liabilities, Net Total liabilities Liabilities Stockholders’ equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Preferred stock, shares issued: none in 2019 and 2018 Preferred Stock, Value, Issued Common stock Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Retained earnings Retained Earnings (Accumulated Deficit) Treasury—common stock shares, at cost: 150,681,543 at September 29, 2019 and 150,172,840 at December 31, 2018 Treasury Stock, Value Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total—The Hershey Company stockholders’ equity Stockholders' Equity Attributable to Parent Noncontrolling interest in subsidiary Stockholders' Equity Attributable to Noncontrolling Interest Total stockholders’ equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and stockholders’ equity Liabilities and Equity Retirement Benefits [Abstract] Schedule of Components of Net Periodic Benefit Cost Schedule of Net Benefit Costs [Table Text Block] Pension and Other Post-Retirement Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Fair Value Hedging Fair Value Hedging [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate swap Interest Rate Swap [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as Hedging Instrument Designated as Hedging Instrument [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Position [Axis] Position [Axis] Position [Domain] Position [Domain] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivative, Fair Value, Net Derivative, Fair Value, Net Derivative asset Derivative Asset Derivative liability Derivative Liability Income Tax Disclosure [Abstract] Income Tax Contingency [Table] Income Tax Contingency [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Effective Income Tax Rate Reconciliation, Percent Effective Income Tax Rate Reconciliation, Percent Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit Tax Cuts and Jobs Act of 2017, change in tax rate, income tax expense Tax Cuts and Jobs Act of 2017, Net Impact Change in Tax Rate and Mandatory Tax on Unremitted Foreign Earnings, Income Tax Expense (Benefit) Tax Cuts and Jobs Act of 2017, Net Impact Change in Tax Rate and Mandatory Tax on Unremitted Foreign Earnings, Income Tax Expense (Benefit) Tax Cuts and Jobs Act of 2017, measurement period adjustment, income tax expense (benefit) Tax Cuts and Jobs Act, Measurement Period Adjustment, Income Tax Expense (Benefit) Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] ONE Brands, LLC ONE Brands, LLC [Member] ONE Brands, LLC [Member] Pirate Brands Pirate Brands [Member] Pirate Brands [Member] Amplify Snack Brands, Inc. Amplify Snack Brands, Inc. [Member] Amplify Snack Brands, Inc. [Member] Business Acquisition and Divestitures [Line Items] Business Acquisition [Line Items] Schedule of Purchase Consideration Allocation to Assets Acquired and Liabilities Assumed Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Share-based Payment Arrangement [Abstract] Pre-tax compensation expense Share-based Payment Arrangement, Expense Related income tax benefit Share-based Payment Arrangement, Expense, Tax Benefit Dividend yields Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Volatility Rate Risk-free interest rates Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected term in years Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Scenario [Axis] Scenario [Axis] Scenario [Domain] Scenario [Domain] Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Trademarks Trademarks [Member] Customer Relationships Customer Relationships [Member] Covenants Noncompete Agreements [Member] Business Acquisition [Line Items] Business Combination, Consideration Transferred Business Combination, Consideration Transferred Finite-Lived Trademarks, Gross Finite-Lived Trademarks, Gross Finite-Lived Customer Relationships, Gross Finite-Lived Customer Relationships, Gross Finite-Lived Noncompete Agreements, Gross Finite-Lived Noncompete Agreements, Gross Finite-Lived Intangible Asset, Useful Life Finite-Lived Intangible Asset, Useful Life Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Customer-related Customer-Related Intangible Assets [Member] Patents Patents [Member] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Finite-lived intangible assets, gross Finite-Lived Intangible Assets, Gross Finite-lived intangible assets, accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Indefinite-lived intangible assets, excluding goodwill Indefinite-lived Intangible Assets (Excluding Goodwill) Pirate Brands [Abstract] Pirate Brands [Abstract] Ownership [Axis] Ownership [Axis] Ownership [Domain] Ownership [Domain] Schedule of Long-Term Debt Instruments Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Net Interest Expense Interest Income and Interest Expense Disclosure [Table Text Block] Restructuring and Related Activities [Abstract] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Cost of Sales Cost of Sales [Member] Selling, marketing and administrative Selling, General and Administrative Expenses [Member] Business realignment charges Restructuring Charges [Member] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Severance Employee Severance [Member] Accelerated depreciation and amortization Accelerated Depreciation and Amortization [Member] Accelerated Depreciation and Amortization [Member] Other program costs Other Restructuring [Member] Facility Closing Facility Closing [Member] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] Restructuring Plan [Axis] Restructuring Plan [Axis] Restructuring Plan [Domain] Restructuring Plan [Domain] Margin for Growth Program Margin for Growth Program [Member] Margin for Growth Program [Member] Operational Optimization Program Operational Optimization Program [Member] Operational Optimization Program [Member] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Business realignment costs Restructuring Charges Derivative [Table] Derivative [Table] Cash Flow Hedges Cash Flow Hedging [Member] Commodities futures and options Commodity Contract [Member] Foreign exchange contracts Foreign Exchange Contract [Member] Interest rate swap agreements Interest Rate Contract [Member] Deferred compensation derivatives Equity Swap [Member] Derivative [Line Items] Derivative [Line Items] Gains (losses) recognized in income Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Gains (losses) on cash flow hedging derivatives, pre-tax amount Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Gains (losses) reclassified from accumulated OCI into income Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Leases [Abstract] Operating leases, Weighted-average remaining lease term Operating Lease, Weighted Average Remaining Lease Term Finance leases, Weighted-average remaining lease term Finance Lease, Weighted Average Remaining Lease Term Operating leases, Weighted-average discount rate Operating Lease, Weighted Average Discount Rate, Percent Finance leases, Weighted-average discount rate Finance Lease, Weighted Average Discount Rate, Percent Organization, Consolidation and Presentation of Financial Statements [Abstract] Inventory, Net [Abstract] Raw materials Inventory, Raw Materials, Net of Reserves Goods in process Inventory, Work in Process, Net of Reserves Finished goods Inventory, Finished Goods, Net of Reserves Inventories at FIFO FIFO Inventory Amount Adjustment to LIFO Inventory, LIFO Reserve Total inventories Prepaid Expense and Other Assets, Current [Abstract] Prepaid Expense and Other Assets, Current [Abstract] Prepaid Expense Prepaid Expense Assets Disposal Group, Including Discontinued Operation, Assets Other Assets, Current Other Assets, Current Prepaid Expenses and Other Prepaid Expenses and Other Prepaid Expenses and Other Property, Plant and Equipment [Abstract] Land Land Buildings Buildings and Improvements, Gross Machinery and equipment Machinery and Equipment, Gross Construction in progress Construction in Progress, Gross Property, plant and equipment, gross Property, Plant and Equipment, Gross Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property, plant and equipment, net Other Assets, Noncurrent [Abstract] Capitalized software, net Capitalized Computer Software, Net Operating lease ROU assets Operating Lease, Right-of-Use Asset Other non-current assets Other Miscellaneous Assets, Non-Current Other Miscellaneous Assets, Non-Current Total other assets Accrued Liabilities, Current [Abstract] Payroll, compensation and benefits Employee-related Liabilities, Current Advertising, promotion and product allowances Accrued Marketing Costs, Current Operating lease liabilities, current Operating Lease, Liability, Current Liabilities Disposal Group, Including Discontinued Operation, Liabilities Other Other Accrued Liabilities, Current Total accrued liabilities Other Liabilities, Noncurrent [Abstract] Post-retirement benefits liabilities Liability, Other Postretirement Defined Benefit Plan, Noncurrent Pension benefits liabilities Liability, Defined Benefit Pension Plan, Noncurrent Operating lease liabilities, non-current Operating Lease, Liability, Noncurrent Other Other Miscellaneous Liabilities, Non-Current Other Miscellaneous Liabilities, Non-Current Total other long-term liabilities Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Foreign currency translation adjustments Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Pension and post-retirement benefit plans, net of tax Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax Cash flow hedges, net of tax AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax Total accumulated other comprehensive loss Derivative Instruments Derivatives and Fair Value [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Non-designated Hedges Not Designated as Hedging Instrument [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Segment Reconciling Items Segment Reconciling Items [Member] Subsegments [Axis] Subsegments [Axis] Subsegments [Domain] Subsegments [Domain] Subsegments Consolidation Items [Axis] Subsegments Consolidation Items [Axis] Subsegments Consolidation Items [Domain] Subsegments Consolidation Items [Domain] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Derivative, Gain (Loss) on Derivative, Net Derivative, Gain (Loss) on Derivative, Net Net gains (losses) on commodity derivative positions reclassified from unallocated to segment income Net Gain Loss On Commodity Derivative Positions Reclassified From Unallocated Derivative Gains Losses To Segment Income The amount of gain (loss) from commodity derivative positions reclassified from unallocated derivative (gains) losses to segment income. Net losses (gains) on mark-to-market valuation of commodity derivative positions recognized in unallocated derivative (gains) losses Net Mark to Market Valuation of Certain Derivative Positions Recognized in Unallocated Derivative (Gains) Losses Changes in the values of derivative positions that is recorded in unallocated derivative (gains)/losses Amplify Snack Brands, Inc [Abstract] Amplify Snack Brands, Inc [Abstract] Cash Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Accounts receivable Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Accounts Receivable Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Accounts Receivable Other current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other Plant, property and equipment, net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Equipment Other intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Other non-current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets Accounts payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Accrued liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accrued Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accrued Liabilities Current debt Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Debt Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Debt Other current liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other Non-current deferred income taxes Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Other long-term liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities Net assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Income Taxes Income Tax Disclosure [Text Block] Inventories Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory Accrued liabilities Schedule of Revenue by Major Customers, by Reporting Segments [Table] Schedule of Revenue by Major Customers, by Reporting Segments [Table] Forecast Forecast [Member] North America North America Segment [Member] North America Segment [Member] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Geographic Concentration Risk Geographic Concentration Risk [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Sales Revenue, Goods, Net Revenue from Contract with Customer Benchmark [Member] Revenue, Major Customer [Line Items] Revenue, Major Customer [Line Items] Concentration Risk, Percentage Concentration Risk, Percentage Derivative, Gain (Loss) on Derivative, Net Cumulative Amount of Mark-to-Market Gaines (Losses) on Commodity Derivatives Cumulative Amount of Mark-to-Market Gaines (Losses) on Commodity Derivatives Short and Long-Term Debt Debt Disclosure [Text Block] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-02 Accounting Standards Update 2016-02 [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Retained Earnings Retained Earnings [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Total operating lease liabilities Operating Lease, Liability Cumulative effect of new accounting principle in period of adoption Cumulative Effect of New Accounting Principle in Period of Adoption Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings Schedule of Components of Lease Expense Lease, Cost [Table Text Block] Schedule of Supplemental Balance Sheet Information Schedule of Supplemental Balance Sheet Information [Table Text Block] Schedule of Supplemental Balance Sheet Information [Table Text Block] Schedule of Maturity of Operating Lease Liabilities Lessee, Operating Lease, Liability, Maturity [Table Text Block] Schedule of Maturity of Finance Lease Liabilities Finance Lease, Liability, Maturity [Table Text Block] Schedule of Supplemental Cash Flow Information Related To Leases Schedule of Supplemental Cash Flow Information Related To Leases [Text Block] Schedule of supplemental cash flow information related to leases. Interest Expense Interest Expense [Member] Derivative, term of contract Derivative, Term of Contract Derivative, notional amount Derivative, Notional Amount Minimum length of time, hedged in cash flow hedge Minimum Length of Time Hedged in Cash Flow Hedge Minimum length of time over which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Maximum length of time, hedged in cash flow hedge Maximum Length of Time Hedged in Cash Flow Hedge Cash flow hedge gain (loss) to be reclassified within twelve months Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Fair value hedges, pre-tax (expense) benefit Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge Corporate, Non-Segment Corporate, Non-Segment [Member] International and Other International and Other Segment [Member] International and Other Segment [Member] Corporate (1) Corporate Segment [Member] Depreciation and amortization Depreciation, Depletion and Amortization Supplemental Balance Sheet Information Supplemental Balance Sheet Disclosures [Text Block] Noncontrolling Interest [Abstract] Noncontrolling Interest [Table] Noncontrolling Interest [Table] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Legal Entity [Axis] Legal Entity [Axis] Entity Entity [Domain] Noncontrolling Interest [Line Items] Noncontrolling Interest [Line Items] Schedule of Activity Relating to the Noncontrolling Interest Schedule of Stockholders Equity [Table Text Block] Line of Credit Facility [Table] Line of Credit Facility [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Line of Credit Line of Credit [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility Revolving Credit Facility [Member] Foreign Line of Credit Foreign Line of Credit [Member] Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] Commercial Paper Commercial Paper [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Line of credit facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Line of credit facility, accordion feature increase limit Line Of Credit Facility, Accordion Feature Increase Limit Line Of Credit Facility, Accordion Feature Increase Limit Short-term foreign bank loans against the lines of credit Line of Credit, Current Short-term debt, weighted average interest rate Short-term Debt, Weighted Average Interest Rate, at Point in Time Lessee, Operating Leases [Text Block] Lessee, Operating Leases [Text Block] Earnings Per Share [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Employee stock options Share-based Payment Arrangement, Option [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive securities excluded from computation of earnings per share (shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule of Goodwill [Table] Schedule of Goodwill [Table] Goodwill [Line Items] Goodwill [Line Items] Goodwill [Roll Forward] Goodwill [Roll Forward] Goodwill, beginning balance Acquired during the period Goodwill, Acquired During Period Foreign currency translation Goodwill, Foreign Currency Translation Gain (Loss) Goodwill, ending balance Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Pension Benefits Pension Plan [Member] Other Benefits Other Postretirement Benefits Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Amounts recognized in net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortization of prior service (credit) cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Amortization of net loss (gain) Defined Benefit Plan, Amortization of Gain (Loss) Settlement loss Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement Total net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Commitments and Contingencies Disclosure [Abstract] Concentration Risk [Table] Concentration Risk [Table] Concentration Risk [Line Items] Concentration Risk [Line Items] Retirement Plan Funding Status [Axis] Retirement Plan Funding Status [Axis] Retirement Plan Funding Status [Domain] Retirement Plan Funding Status [Domain] Retirement Plan Name [Axis] Retirement Plan Name [Axis] Retirement Plan Name [Domain] Retirement Plan Name [Domain] Defined Benefit Plan, Plan Assets, Contributions by Employer Defined Benefit Plan, Plan Assets, Contributions by Employer Defined Benefit Plan, Remeasurement, Basis Spread on Discount Rate Defined Benefit Plan, Remeasurement, Basis Spread on Discount Rate Defined Benefit Plan, Remeasurement, Basis Spread on Discount Rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets Earnings Per Share Earnings Per Share [Text Block] Basis of Presentation Business Description and Basis of Presentation [Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding shares at beginning of year (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Exercised (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Forfeited (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Outstanding as of September 29, 2019 (shares) Options exercisable as of September 29, 2019 (shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Outstanding at beginning of year (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Granted (USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Exercises (USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Forfeited (USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Outstanding as of September 29, 2019 (USD per share) Options exercisable as of September 29, 2019 (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Options outstanding, weighted-average remaining contractual term Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Options exercisable, weighted aver remaining contractual term Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Aggregate intrinsic value of options outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Aggregate intrinsic value of options exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Performance and restricted stock units Performance Shares And Restricted Stock Units (RSU) [Member] Performance Shares And Restricted Stock Units (RSU) [Member] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Basic earnings per share: Earnings Per Share, Basic, Two Class Method [Abstract] Allocation of distributed earnings (cash dividends paid) Dividends Allocation of undistributed earnings Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Total earnings—basic Participating Securities, Distributed and Undistributed Earnings (Loss), Basic Total weighted-average shares—basic (shares) Weighted Average Number of Shares Outstanding, Basic Earnings Per Share—basic (USD per share) Earnings Per Share, Basic Diluted earnings per share: Earnings Per Share, Diluted, Two Class Method [Abstract] Allocation of total earnings used in basic computation Reallocation of total earnings as a result of conversion of Class B common stock to Common stock Distributed Earnings Reallocation of undistributed earnings Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted Total earnings—diluted Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted Conversion of Class B common stock to Common shares outstanding Incremental Common Shares Attributable to Dilutive Effect of Conversion of Common Stock Incremental Common Shares Attributable to Dilutive Effect of Conversion of Common Stock Incremental common shares attributable to dilutive effect of share-based payment arrangements Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Total weighted-average shares—diluted (shares) Weighted Average Number of Shares Outstanding, Diluted Earnings Per Share—diluted (USD per share) Earnings Per Share, Diluted Operating leases Lessee, Operating Lease, Liability, Payment, Due [Abstract] 2019 (remaining of year) Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year 2020 Lessee, Operating Lease, Liability, Payments, Due Year Two 2021 Lessee, Operating Lease, Liability, Payments, Due Year Three 2022 Lessee, Operating Lease, Liability, Payments, Due Year Four 2023 Lessee, Operating Lease, Liability, Payments, Due Year Five Thereafter Lessee, Operating Lease, Liability, Payments, Due after Year Five Total lease payments Lessee, Operating Lease, Liability, Payments, Due Less: Imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Finance leases Finance Lease, Liability, Payment, Due [Abstract] 2019 (remaining of year) Finance Lease, Liability, Payments, Remainder of Fiscal Year 2020 Finance Lease, Liability, Payments, Due Year Two 2021 Finance Lease, Liability, Payments, Due Year Three 2022 Finance Lease, Liability, Payments, Due Year Four 2023 Finance Lease, Liability, Payments, Due Year Five Thereafter Finance Lease, Liability, Payments, Due after Year Five Total lease payments Finance Lease, Liability, Payment, Due Less: Imputed interest Finance Lease, Liability, Undiscounted Excess Amount Total finance lease liabilities 2019 (remaining of year) Lessee Operating and Financing Lease Liability Payments Remainder Of Fiscal Year Amount of lessee's undiscounted obligation for lease payments for operating and finance leases having an initial or remaining lease term in excess of one year due in remainder of fiscal year following latest fiscal year. 2020 Lessee Operating and Financing Lease Liability Payments Due Year Two Amount of lessee's undiscounted obligation for lease payments for operating and finance leases, due in second fiscal year following latest fiscal year 2021 Lessee Operating and Financing Lease Liability Payments Due Year Three Amount of lessee's undiscounted obligation for lease payments for operating and finance leases, due in third fiscal year following latest fiscal year 2022 Lessee Operating and Financing Lease Liability Payments Due Year Four Amount of lessee's undiscounted obligation for lease payments for operating and finance leases, due in fourth fiscal year following latest fiscal year. 2023 Lessee Operating and Financing Lease Liability Payments Due Year Five Amount of lessee's undiscounted obligation for lease payments for operating and finance leases, due in fifth fiscal year following latest fiscal year. Thereafter Lessee Operating and Financing Lease Liability Payments Due After Year Five Amount of lessee's undiscounted obligation for lease payments for operating lease, due after fifth fiscal year following latest fiscal year. Total lease payments Lessee Operating and Financing Lease Liability Payments Due Amount of lessee's undiscounted obligation for lease payments for operating and finance leases. Less: Imputed interest Lessee Operating and Fiannce Lease Liability Undiscounted Excess Amount Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating and finance leases. Total lease liabilities Operating & Finance, Lease Liability Present value of lessee's discounted obligation for lease payments from operating and finance leases. Stock Compensation Plans Share-based Payment Arrangement [Text Block] Business Acquisitions Mergers, Acquisitions and Dispositions Disclosures [Text Block] Restructuring Reserve [Roll Forward] Restructuring Reserve [Roll Forward] Liability balance at December 31, 2018 Restructuring Reserve 2019 business realignment charges Restructuring Charges, Business Realignment Reserve Restructuring Charges, Business Realignment Reserve Cash payments Payments for Restructuring Liability balance at September 29, 2019 Schedule of Stock Compensation Costs Share-based Payment Arrangement, Cost by Plan [Table Text Block] Schedule of Activity Relating to the Grants of Stock Options Share-based Payment Arrangement, Option, Activity [Table Text Block] Schedule of Fair Value Estimated on the Grant Date and the Weighted Average Assumptions Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule of Activity Relating to Grants of PSUs and RSUs Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Schedule of Information Pertaining to Fair Value of PSUs and RSUs Granted for Potential Future Distribution Schedule of Share-based Payment Award, Equity Instruments Other than Options, Valuation Assumptions [Table Text Block] Schedule of Share-based Payment Award, Equity Instruments Other than Options, Valuation Assumptions [Table Text Block] Income Statement [Abstract] Net sales Revenue from Contract with Customer, Excluding Assessed Tax Cost of sales Cost of Goods and Services Sold Gross profit Gross Profit Selling, marketing and administrative expense Selling, General and Administrative Expense Long-lived asset impairment charges Asset Impairment Charges Business realignment costs Restructuring Charges, Business Realignment Restructuring Charges, Business Realignment Operating profit Operating Income (Loss) Interest expense, net Other (income) expense, net Other Nonoperating Income (Expense) Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Provision for income taxes Income Tax Expense (Benefit) Net income including noncontrolling interest Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net (loss) income attributable to noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to The Hershey Company Net Income (Loss) Attributable to Parent Net income per share—basic: Earnings Per Share, Basic [Abstract] Net income per share - basic (USD per share) Net income per share—diluted: Earnings Per Share, Diluted [Abstract] Net income per share - diluted (USD per share) Dividends paid per share: Dividends, Common Stock [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Performance stock units and restricted stock units Performance Stock Units and Restricted Stock Units [Member] Performance Stock Units and Restricted Stock Units [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Employee service share-based compensation, nonvested awards, compensation cost not yet recognized Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Intrinsic value of options exercised (in millions of dollars) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Intrinsic value of share-based liabilities paid, combined with the fair value of shares vested (in millions of dollars) Share Based Compensation Arrangement By Share Based Payment Award Intrinsic Value Of Share Based Liabilities Paid Combined With Fair Value Of Shares Vested Intrinsic value of share-based liabilities paid, combined with the fair value of shares vested (in millions of dollars). Deferred performance stock units, deferred restricted stock units, and directors' fees and accumulated dividend amounts representing deferred stock units outstanding Deferred Compensation Arrangement with Individual, Shares Issued Common stock, conversion basis (shares) Deferred Compensation Arrangement with Individual, Conversion Basis Deferred Compensation Arrangement with Individual, Conversion Basis Operating Income (Loss) Unallocated corporate expense Nonoperating Income (Expense) Long-lived asset impairment charges Goodwill and Intangible Asset Impairment Costs associated with business realignment activities (see Note 9) Acquisition-related costs Business Combination, Integration Related Costs Gain on sale of licensing rights Gain (Loss) on Disposition of Intangible Assets Income before income taxes Schedule of Treasury Stock Activity Schedule of Common Stock Outstanding Roll Forward [Table Text Block] Other Income and Expenses [Abstract] Other (Income) Expense, Net Schedule of Other Nonoperating Income (Expense) [Table Text Block] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Significant other unobservable inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Fair Value, Net Asset (Liability) Fair Value, Net Asset (Liability) Business Realignment Activities Restructuring, Impairment, and Other Activities Disclosure [Text Block] Discontinued Operations and Disposal Groups [Abstract] Assets and Liabilities Held for Sale Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Lotte Shanghai Food Company [Member] Lotte Shanghai Food Company [Member] Lotte Shanghai Food Company [Member] Noncontrolling Interest in Subsidiary Noncontrolling Interest [Member] Noncontrolling Interest, Ownership Percentage by Parent Noncontrolling Interest, Ownership Percentage by Parent Operating lease cost Operating Lease, Cost Amortization of ROU assets, Finance lease cost Finance Lease, Right-of-Use Asset, Amortization Interest on lease liabilities, Finance lease cost Finance Lease, Interest Expense Net lease cost Lease, Cost Cover page. Entities [Table] Entities [Table] Entity Information [Line Items] Entity Information [Line Items] Document Type Document Type Document Quarterly Report Document Quarterly Report Document Period End Date Document Period End Date Document Transition Report Document Transition Report Entity File Number Entity File Number Entity Registrant Name Entity Registrant Name Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address, Address Line One Entity Address, City or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province Entity Address, Postal Zip Code Entity Address, Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Title of 12(b) Security Title of 12(b) Security Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Assets and Liabilities Held for Sale Disposal Groups, Including Discontinued Operations [Table Text Block] Property, plant and equipment, net Disposal Group, Including Discontinued Operation, Property, Plant and Equipment Other assets Disposal Group, Including Discontinued Operation, Other Assets Assets Accounts payable and accrued liabilities Disposal Group, Including Discontinued Operation, Accounts Payable and Accrued Liabilities Liabilities Proceeds from Sale of Intangible Assets Proceeds from Sale of Intangible Assets Proceeds from sales of property, plant and equipment and other long-lived assets Proceeds from Sale of Property, Plant, and Equipment Business realignment costs Proceeds from Divestiture of Businesses Proceeds from Divestiture of Businesses Schedule of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fair Value Disclosures [Abstract] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Recurring [Member] Quoted prices in active markets of identical assets (Level 1) Fair Value, Inputs, Level 1 [Member] Significant other observable inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Derivative liability Preferred stock, shares issued (shares) Preferred Stock, Shares Issued Common stock, shares issued (shares) Common Stock, Shares, Issued Treasury stock, shares (shares) Treasury Stock, Shares Other current assets FAIR VALUE MEASUREMENTS [Abstract] FAIR VALUE MEASUREMENTS [Abstract] Fair Value Measurements Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block] Schedule of Other (Income) Expense, Net Other Income and Other Expense Disclosure [Text Block] Gross derivative assets, included within derivative liabilities Derivative Asset, Cash Transfers Receivable (Payable), Change In Quoted Market Prices On The Last Day Of Trading Derivative Asset, Cash Transfers Receivable (Payable), Change In Quoted Market Prices On The Last Day Of Trading Derivative liability, gross liabilities Derivative Liability, Cash Transfers Receivable (Payable), Change In Quoted Market Prices On The Last Day Of Trading Derivative Liability, Cash Transfers Receivable (Payable), Change In Quoted Market Prices On The Last Day Of Trading Contingencies Commitments and Contingencies Disclosure [Text Block] Statement of Comprehensive Income [Abstract] Restatement [Axis] Restatement [Axis] Restatement [Domain] Restatement [Domain] Net income including noncontrolling interest Other comprehensive income (loss), net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Foreign currency translation adjustments, pre-tax amount Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax Foreign currency translation adjustments, tax (expense) benefit Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Foreign currency translation adjustments, after-tax amount Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Reclassification to earnings due to the sale of businesses, pre-tax amount Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax Reclassification to earnings due to the sale of businesses, tax (expense) benefit Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Tax Reclassification to earnings due to the sale of businesses, after-tax amount Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax Pension and post-retirement benefit plans: Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract] Net actuarial gain (loss) and prior service cost, pre-tax amount Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax Net actuarial gain (loss) and prior service cost, tax (expense) benefit Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax Net actuarial gain (loss) and prior service cost, after-tax amount Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax Tax cuts and jobs act, reclassification from aoci to retained earnings, pre tax effect, pension and post-retirement benefit plans Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Pre Tax Effect, Pension and Post-retirement Benefit Plans Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Pre Tax Effect, Pension and Post-retirement Benefit Plans Tax cuts and jobs act, reclassification from aoci to retained earnings, tax effect, pension and post-retirement benefit plans Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Tax Effect, Pension and Post-retirement Benefit Plans Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Tax Effect, Pension and Post-retirement Benefit Plans Tax cuts and jobs act, reclassification from aoci to retained earnings, after tax pension and post-retirement benefit plans Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, After Tax Pension and Post-retirement Benefit Plans Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, After Tax Pension and Post-retirement Benefit Plans Reclassification to earnings, pre-tax amount Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax Reclassification to earnings, tax (expense) benefit Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax Reclassification to earnings, after-tax amount Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax Cash flow hedges: Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract] Gains (losses) on cash flow hedging derivatives, tax (expense) benefit Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax Gains (losses) on cash flow hedging derivatives, after-tax amount Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Pre Tax Effect, Cash Flow Hedges Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Pre Tax Effect, Cash Flow Hedges Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Pre Tax Effect, Cash Flow Hedges Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Tax Effect, Cash Flow Hedges Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Tax Effect, Cash Flow Hedges Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Tax Effect, Cash Flow Hedges Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, After Tax, Cash Flow Hedges Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, After Tax, Cash Flow Hedges Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, After Tax, Cash Flow Hedges Reclassification to earnings, pre-tax amount Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Reclassification to earnings, tax (expense) benefit Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Reclassification to earnings, after-tax amount Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Total other comprehensive income (loss), pre-tax amount Other Comprehensive Income (Loss), before Tax Total other comprehensive income (loss), tax (expense) benefit Other Comprehensive Income (Loss), Tax Total other comprehensive income (loss), after-tax amount Other Comprehensive Income (Loss), Net of Tax Total comprehensive income including noncontrolling interest Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive income attributable to noncontrolling interest Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to The Hershey Company Comprehensive Income (Loss), Net of Tax, Attributable to Parent Operating cash flows from operating leases Operating Lease, Payments Operating cash flows from finance leases Finance Lease, Interest Payment on Liability Financing cash flows from finance leases Finance Lease, Principal Payments Operating leases Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Finance leases Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Finance lease ROU assets, at cost Finance Lease, Right Of Use Asset, Gross Finance Lease, Right Of Use Asset, Gross Accumulated amortization Finance Lease, Right-Of-Use Asset, Accumulated Depreciation Finance Lease, Right-Of-Use Asset, Accumulated Depreciation Finance lease ROU assets, net Finance Lease, Right-of-Use Asset Total leased assets Lease, Right-of-Use Asset Lease, Right-of-Use Asset Finance lease liabilities, current Finance Lease, Liability, Current Finance lease liabilities, non-current Finance Lease, Liability, Noncurrent Total leased assets Lease, Liability Lease, Liability Business Acquisition, Share Price Business Acquisition, Share Price Business Acquisition, Equity Interests Received, Common Stock, Value Business Acquisition, Equity Interests Received, Common Stock, Value Business Acquisition, Equity Interests Received, Common Stock, Value Business Combination, Acquisition Related Costs Business Combination, Acquisition Related Costs Schedule of Business Realignment Activity Restructuring and Related Costs [Table Text Block] Schedule of Liability Activity for Costs Qualifying as Exit and Disposal Costs Schedule of Restructuring Reserve by Type of Cost [Table Text Block] Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Outstanding at beginning of year (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Performance assumption change (shares) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Performance Assumption Change The change in the number of shares under a share-based award plan other than a stock option plan due to a change in the performance assumptions. Vested (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Outstanding at September 29, 2019 (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Outstanding at beginning of year (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Weighted-average fair value at date of grant (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Performance assumption change Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Performance Assumption Change Weighted Average Grant Date Fair Value The weighted average fair value as of the grant date pertaining to a share-based award plan other than a stock option plan due to a change in the performance assumptions. Vested (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Outstanding at September 29, 2019 (USD per share) Interest rate, stated percentage Debt Instrument, Interest Rate, Stated Percentage Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Current portion of long-term debt, Fair value Long-term Debt, Current Maturities, Fair Value Long-term Debt, Current Maturities, Fair Value Long-term debt, Fair value Long-term Debt, Excluding Current Maturities, Fair Value Long-term Debt, Excluding Current Maturities, Fair Value Total long-term debt, Fair Value Long-term Debt, Fair Value Noncontrolling Interest Noncontrolling Interest Disclosure [Text Block] Amortization of Intangible Assets Amortization of Intangible Assets Preferred Stock Preferred Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Treasury Common Stock Treasury Stock [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Noncontrolling Interests in Subsidiaries Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance, stockholders' equity Net income attributable to The Hershey Company Net (loss) income attributable to noncontrolling interest Other comprehensive income (loss) Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Dividends (including dividend equivalents): Common Stock Dividends, Common Stock, Cash Stock-based compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition Exercise of stock options and incentive-based transactions Stock Issued During Period, Value, Stock Options Exercised Repurchase of common stock Treasury Stock, Value, Acquired, Cost Method Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Tax Effect Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Tax Effect Tax Cuts and Jobs Act, Reclassification From AOCI To Retained Earnings, Tax Effect Ending balance, stockholders' equity Class of Treasury Stock [Table] Class of Treasury Stock [Table] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] 2017 Share Repurchase Program 2017 Share Repurchase Program [Member] 2017 Share Repurchase Program [Member] 2018 Share Repurchase Program 2018 Share Repurchase Program [Member] 2018 Share Repurchase Program [Member] Equity, Class of Treasury Stock [Line Items] Equity, Class of Treasury Stock [Line Items] Stock Repurchase Program, Authorized Amount Stock Repurchase Program, Authorized Amount Stock Repurchase Program, Remaining Authorized Repurchase Amount Stock Repurchase Program, Remaining Authorized Repurchase Amount Segment Information Segment Reporting Disclosure [Text Block] Schedule of Assets and Liabilities Measured at Fair Value Fair Value Measurements, Nonrecurring [Table Text Block] Schedule of Fair Values and Carrying Values of Long-Term Debt Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Common stock Hershey Common Stock [Member] Hershey Common Stock [Member] Class of Stock [Line Items] Class of Stock [Line Items] Treasury Stock, Shares, Acquired Treasury Stock, Shares, Acquired Shares Issued, Shares, Share-based Payment Arrangement, before Forfeiture Shares Issued, Shares, Share-based Payment Arrangement, before Forfeiture Treasury Stock Change in Shares Treasury Stock Change in Shares Change in the number of common shares that were previously issued and that were repurchased by the issuing entity and held in treasury during the period. This stock has no voting rights and receives no dividends. Stock Repurchased During Period, Value Stock Repurchased During Period, Value Shares Issued, Value, Share-based Payment Arrangement, before Forfeiture Shares Issued, Value, Share-based Payment Arrangement, before Forfeiture Treasury Stock Change in Value Treasury Stock Change in Value Change in value of common shares of an entity that were issued, repurchased by the entity, and are held in its treasury during the period. Treasury stock is issued but is not outstanding. This stock has no voting rights and receives no dividends. Note that treasury stock may be recorded at its total cost or separately as par (or stated) value and additional paid in capital. Note: number of treasury shares concept is in another section within stockholders' equity. Write-down of equity investments in partnerships qualifying for tax credits Equity Method Investment, Other than Temporary Impairment Non-service cost components of net periodic benefit cost relating to pension and other post-retirement benefit plans Defined Benefit Plan, Non-Service Cost Defined Benefit Plan, Non-Service Cost Other (income) expense, net Other Nonoperating, Gain (Loss) Other Nonoperating, Gain (Loss) Total North America North America [Member] Restructuring and related cost, expected cost Restructuring and Related Cost, Expected Cost Restructuring and Related Cost, Cost Incurred to Date Restructuring and Related Cost, Cost Incurred to Date Restructuring and Related Cost, Expected Cost, Cash Portion Restructuring and Related Cost, Expected Cost, Cash Portion Restructuring and Related Cost, Expected Cost, Cash Portion Restructuring and Related Cost, Number of Positions Eliminated, Inception to Date Percent Restructuring and Related Cost, Number of Positions Eliminated, Inception to Date Percent Balance, December 31, 2018 Other comprehensive loss - foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest Balance, September 29, 2019 Units granted (shares) Estimated values (USD per share) Share Price Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Schedule of Net Sales and Earnings by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Unallocated Mark-to-Market (Gains) Losses on Commodity Derivatives Allocation Of Net Derivative Gains Losses From Economic Hedges To Operating Results Of Reporting Segments Table [Table Text Block] Allocation Of Net Derivative Gains Losses From Economic Hedges To Operating Results Of Reporting Segments Table [Table Text Block] Schedule of Depreciation and Amortization Expense Included within Segment Income Reconciliation of Other Significant Reconciling Items from Segments to Consolidated [Table Text Block] Statement of Cash Flows [Abstract] Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Stock-based compensation expense Share-based Payment Arrangement, Noncash Expense Deferred income taxes Deferred Income Taxes and Tax Credits Impairment of long-lived assets Restructuring Costs and Asset Impairment Charges Write-down of equity investments Other Other Operating Activities, Cash Flow Statement Changes in assets and liabilities, net of business acquisitions and divestitures: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable—trade, net Increase (Decrease) in Accounts Receivable Inventories Increase (Decrease) in Inventories Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Accrued income taxes Increase (Decrease) in Accrued Taxes Payable Contributions to pension and other benefit plans Payment for Pension and Other Postretirement Benefits Other assets and liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Capital additions (including software) Payments to Acquire Property, Plant, and Equipment Proceeds from sales of businesses, net of cash and cash equivalents divested Equity investments in tax credit qualifying partnerships Payments to Acquire Equity Method Investments Business acquisitions, net of cash and cash equivalents acquired Payments to Acquire Businesses, Net of Cash Acquired Other investing activities Payments for (Proceeds from) Other Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Increase in short-term debt Proceeds from (Repayments of) Short-term Debt Long-term borrowings Proceeds from Issuance of Long-term Debt Repayment of long-term debt and finance leases Repayments of Long-term Debt Repayment of tax receivable obligation Repayment of Tax Receivable Obligation Repayment of Tax Receivable Obligation Cash dividends paid Payments of Ordinary Dividends, Common Stock Repurchase of common stock Payments for Repurchase of Common Stock Exercise of stock options Proceeds from Stock Options Exercised Net cash (used in) provided by financing activities Net Cash Provided by (Used in) Financing Activities Effect of exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents (Decrease) Increase in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Supplemental Disclosure Supplemental Cash Flow Information [Abstract] Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activities Income taxes paid Income Taxes Paid, Net