Employee Benefit Plans - Summary of Retirement Plan Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Employee Benefit Plans [Line Items]
Retirement plan expense	$ 51,332	$ 42,937	$ 56,914
Defined benefit pension plans
Schedule of Employee Benefit Plans [Line Items]
Retirement plan expense	9,815	12,366	7,428
Defined contribution retirement plans
Schedule of Employee Benefit Plans [Line Items]
Retirement plan expense	32,743	35,318	38,508
Postretirement benefit plans
Schedule of Employee Benefit Plans [Line Items]
Retirement plan expense	(2,220)	(2,148)	963
Deferred compensation and excess benefit plans
Schedule of Employee Benefit Plans [Line Items]
Retirement plan expense	$ 10,994	$ (2,599)	$ 10,015