Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost (income)	$ (394)	$ (368)	$ (1,178)	$ (845)
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	1,235	1,149	3,704	3,503
Expected return on plan assets	(2,201)	(2,590)	(6,602)	(7,761)
Amortization of net actuarial loss	577	1,045	1,731	3,333
Net periodic benefit cost (income)	(389)	(396)	(1,167)	(925)
United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	86	90	282	269
Expected return on plan assets	(93)	(80)	(300)	(242)
Amortization of net actuarial loss	2	18	7	53
Net periodic benefit cost (income)	$ (5)	$ 28	$ (11)	$ 80