Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	$ (610)	$ (28)	$ (690)
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	6,605	6,949	4,923
Expected return on plan assets	(8,479)	(8,533)	(8,802)
Amortization of net actuarial (gain) loss	(12)	(23)	2,277
Net periodic benefit cost	(1,886)	(1,607)	(1,602)
United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	647	669	374
Expected return on plan assets	(735)	(695)	(399)
Amortization of net actuarial (gain) loss	324	334	9
Net periodic benefit cost	$ 236	$ 308	$ (16)