Retirement Plans - Schedule of Defined Benefit Plans Disclosures (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Fair value of plan assets at beginning of year	$ 0	$ 0
Employer contribution	1,475	1,391
Benefit payments	(1,475)	(1,391)
Fair value of plan assets at end of year	0	0
Funded status	(32,640)	(31,001)
Accrued expenses	(1,447)	(1,478)
Other non-current liabilities	(31,193)	(29,523)
Net amount recognized	(32,640)	(31,001)
Net actuarial loss	10,760	8,940
Prior service cost	(1)	(1)
Net amount recognized, before tax effect	$ 10,759	$ 8,939
Discount rate	2.60%	3.30%
Rate of compensation increase	3.00%	3.00%