CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income including noncontrolling interest	$ 1,275,413	$ 1,146,752	$ 1,171,051
Other comprehensive income (loss), net of tax:
Foreign currency translation (losses) gains during period, pre-tax amount	(13,767)	13,141	(31,143)
Foreign currency translation (losses) gains during period, tax (expense) benefit	0	0	0
Foreign currency translation (losses) gains during period, after-tax amount	(13,767)	13,141	(31,143)
Reclassification to earnings due to sale of businesses, pre-tax amount	0	0	(25,131)
Reclassification to earnings due to sale of businesses, pre-tax amount, tax (expense) benefit	0	0	0
Reclassification to earnings due to sale of businesses, after-tax amount	0	0	(25,131)
Pension and post-retirement benefit plans:
Net actuarial (loss) gain and prior service cost, pre-tax amount	(39,455)	(9,315)	(39,724)
Net actuarial (loss) gain and prior service cost, tax (expense) benefit	9,351	2,273	10,120
Net actuarial (loss) gain and prior service cost, after-tax amount	(30,104)	(7,042)	(29,604)
Reclassification of tax effects relating to U.S. tax reform, pre-tax amount	0	0	0
Reclassification of tax effects relating to U.S. tax reform, tax (expense) benefit	0	0	(36,535)
Reclassification of tax effects relating to U.S. tax reform, after-tax amount	0	0	(36,535)
Reclassification to earnings, pre-tax amount	33,326	31,341	40,421
Reclassification to earnings, tax (expense) benefit	(8,240)	(8,256)	(9,986)
Reclassification to earnings, after-tax amount	25,086	23,085	30,435
Cash flow hedges:
(Losses) gains on cash flow hedging derivatives, before tax	(780)	(2,515)	5,822
(Losses) gains on cash flow hedging derivatives, tax	(1,880)	(857)	86
(Losses) gains on cash flow hedging derivatives, after tax	1,100	(1,658)	5,736
Reclassification of tax effects relating to U.S. tax reform, pre-tax amount	0	0	0
Reclassification of tax effects relating to U.S. tax reform, tax (expense) benefit	0	0	(11,121)
Reclassification of tax effects relating to U.S. tax reform, after-tax amount	0	0	(11,121)
Reclassification to earnings, pre-tax amount	7,779	8,404	5,573
Reclassification to earnings, tax (expense) benefit	(3,156)	(2,949)	(2,677)
Reclassification to earnings, after-tax amount	4,623	5,455	2,896
Total other comprehensive (loss) income, pre-tax amount	(12,897)	41,056	6,080
Total other comprehensive (loss) income, tax (expense) benefit	(165)	(8,075)	(50,285)
Total other comprehensive (loss) income, after-tax amount	(13,062)	32,981	(44,205)
Total comprehensive income including noncontrolling interest	1,262,351	1,179,733	1,126,846
Comprehensive loss attributable to noncontrolling interest	(2,241)	(2,773)	(7,682)
Comprehensive income attributable to The Hershey Company	$ 1,264,592	$ 1,182,506	$ 1,134,528