Pension and Other Postretirement Benefits - Schedule of Funded Status of the Plans (Detail) £ in Thousands, $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2023 GBP (£)	Dec. 31, 2022 USD ($)	Dec. 31, 2022 GBP (£)	Dec. 31, 2021 USD ($)
Foreign Defined Benefits Pension Plans [Member]
Funded status of the plans:
Fair value of plan assets	$ 42,338	£ 33,257	$ 41,679	£ 34,475
Defined Benefit Pension Plan [Member] | U.S. [Member]
Funded status of the plans:
Fair value of plan assets	163,929		161,374		$ 214,937
Less benefit obligations	194,365		193,670		260,301
Funded status at December 31	(30,436)		(32,296)
Defined Benefit Pension Plan [Member] | Foreign Defined Benefits Pension Plans [Member]
Funded status of the plans:
Fair value of plan assets	42,338		41,679		71,614
Less benefit obligations	42,447		39,319		67,007
Funded status at December 31	(109)		2,360
Other Postretirement Benefit Plans [Member]
Funded status of the plans:
Less benefit obligations	7,748		7,644		$ 10,430
Funded status at December 31	$ (7,748)		$ (7,644)