Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	$ (302)	$ 874	$ 351
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	4,671	5,668	6,616
Expected return on plan assets	(10,348)	(9,747)	(9,450)
Amortization of net actuarial loss	4,444	4,262	2,490
Net periodic benefit cost	(1,233)	183	(344)
United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	357	445	554
Expected return on plan assets	(320)	(548)	(787)
Amortization of net actuarial loss	129	79	244
Net periodic benefit cost	$ 166	$ (24)	$ 11