CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Cumulative effect of new accounting principle in period of adoption	Common stock	Class B common stock	Preferred Stock	Common stock Common stock	Common stock Class B common stock	Additional Paid-in Capital	Retained Earnings	Retained Earnings Cumulative effect of new accounting principle in period of adoption	Retained Earnings Common stock	Retained Earnings Class B common stock	Treasury Common Stock	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests in Subsidiaries
Beginning balance, stockholders' equity at Dec. 31, 2017	$ 931,565				$ 0	$ 299,281	$ 60,620	$ 924,978	$ 6,371,082				$ (6,426,877)	$ (313,746)	$ 16,227
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to The Hershey Company	1,177,562								1,177,562
Net income (loss) attributable to noncontrolling interests	(6,511)														(6,511)
Net income including noncontrolling interest	1,171,051
Other comprehensive income (loss)	3,451													4,622	(1,171)
Dividends (including dividend equivalents):
Common Stock			$ (412,491)	$ (151,789)							$ (412,491)	$ (151,789)
Stock Issued During Period, Value, Conversion of Convertible Securities	0		6	(6)
Stock-based compensation	49,656							49,656
Exercise of stock options and incentive-based transactions	63,323							7,571					55,752
Repurchase of common stock	(247,500)												(247,500)
Tax cuts and jobs act, reclassification from aoci to retained earnings, tax effect	0								47,656					(47,656)
Ending balance, stockholders' equity at Dec. 31, 2018	1,407,266				0	299,287	60,614	982,205	7,032,020				(6,618,625)	(356,780)	8,545
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to The Hershey Company	1,149,692								1,149,692
Net income (loss) attributable to noncontrolling interests	(2,940)														(2,940)
Net income including noncontrolling interest	1,146,752
Other comprehensive income (loss)	32,981													32,814	167
Dividends (including dividend equivalents):
Common Stock			(445,618)	(164,627)							(445,618)	(164,627)
Stock-based compensation	50,732							50,732
Exercise of stock options and incentive-based transactions	240,806							109,273					131,533
Repurchase of common stock	(527,211)												(527,211)
Retirement of treasury common stock	0					(138,348)			(6,284,919)				6,423,267
Ending balance, stockholders' equity at Dec. 31, 2019	1,744,994	$ 3,913			0	160,939	60,614	1,142,210	1,290,461	$ 3,913			(591,036)	(323,966)	5,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to The Hershey Company	1,278,708								1,278,708
Net income (loss) attributable to noncontrolling interests	(3,295)														(3,295)
Net income including noncontrolling interest	1,275,413
Other comprehensive income (loss)	(13,062)													(14,116)	1,054
Dividends (including dividend equivalents):
Common Stock			$ (466,777)	$ (173,719)							$ (466,777)	$ (173,719)
Stock-based compensation	56,698							56,698
Exercise of stock options and incentive-based transactions	25,532							(7,708)					33,240
Repurchase of common stock	(211,196)												(211,196)
Ending balance, stockholders' equity at Dec. 31, 2020	$ 2,237,883				$ 0	$ 160,939	$ 60,614	$ 1,191,200	$ 1,928,673				$ (768,992)	$ (338,082)	$ 3,531