Benefit Plans - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020 USD ($) Plan shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Compensation And Retirement Disclosure [Abstract]
Employer discretionary contribution amount	$ 8,300,000	$ 5,300,000	$ 5,900,000
Number of non-contributory defined benefit pension plans | Plan	2
Period of average compensation for pension benefit computation	5 years
Deferred compensation arrangement with Individual, recorded liability	$ 8,900,000
Deferred compensation arrangement with individual, value of shares issued	$ 8,925,065
Deferred compensation arrangement with individual, shares issued | shares	553,665
Long-term portion of the pension liability	$ 33,200,000	37,200,000
AOCI net prior service cost	10,900,000
Future amortization of prior service cost	$ 800,000
Retirement age	65 years
Rabbi trust balance	$ 35,700,000
Expense related to contributions	100,000	100,000	$ 100,000
Total deferred compensation liability	36,900,000	29,500,000
Deferred compensation liability, current	$ 2,000,000.0	$ 1,500,000