Pension and other postretirement benefits - Amounts recognized in accumulated other comprehensive (income) loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan, Chance in Amounts Recognized in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance, accumulated other comprehensive (income) loss, net of tax	$ 403,522
Impact of currency translation, accumulated other comprehensive (income) loss, net of tax	(44,902)	$ 62,904	$ 63,191
Ending balance, accumulated other comprehensive (income) loss, net of tax	314,405	403,522
Pension
Defined Benefit Plan, Chance in Amounts Recognized in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance, prior service cost (credit)	200	200
Net amortization and deferral, prior service cost	(9)	0
Actuarial changes in benefit obligation, prior service cost	0	0
Impact of currency translation, prior service cost (credit)	0	0
Ending balance, prior service cost (credit)	191	200	200
Beginning balance, net (gain) or loss	219,355	217,939
Net amortization and deferral, net (gain) or loss	(8,527)	(7,900)
Actuarial changes in benefit obligation, net gain (loss)	(47,453)	10,724
Impact of currency translation, net (gain) or loss	573	(1,408)
Ending balance, net (gain) or loss	163,948	219,355	217,939
Beginning balance, deferred taxes	(77,347)	(77,273)
Net amortization and deferral, deferred taxes	1,961	1,832
Actuarial changes in benefit obligation, deferred taxes	10,805	(2,271)
Impact of currency translation, deferred taxes	(139)	365
Ending balance, deferred taxes	(64,720)	(77,347)	(77,273)
Beginning balance, accumulated other comprehensive (income) loss, net of tax	142,208	140,866
Net amortization and deferral, accumulated other comprehensive (income) loss, net of tax	(6,575)	(6,068)
Actuarial changes in benefit obligation, accumulated other comprehensive income (loss), net of tax	(36,648)	8,453
Impact of currency translation, accumulated other comprehensive (income) loss, net of tax	434	(1,043)
Ending balance, accumulated other comprehensive (income) loss, net of tax	99,419	142,208	140,866
Other Benefits
Defined Benefit Plan, Chance in Amounts Recognized in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance, prior service cost (credit)	(2,635)	(3,652)
Net amortization and deferral, prior service cost	1,017	1,017
Actuarial changes in benefit obligation, prior service cost	0	0
Ending balance, prior service cost (credit)	(1,618)	(2,635)	(3,652)
Beginning balance, net (gain) or loss	(5,177)	805
Net amortization and deferral, net (gain) or loss	547	241
Actuarial changes in benefit obligation, net gain (loss)	(7,996)	(6,223)
Ending balance, net (gain) or loss	(12,626)	(5,177)	805
Beginning balance, deferred taxes	1,403	271
Net amortization and deferral, deferred taxes	(359)	(287)
Actuarial changes in benefit obligation, deferred taxes	1,830	1,419
Ending balance, deferred taxes	2,874	1,403	271
Beginning balance, accumulated other comprehensive (income) loss, net of tax	(6,409)	(2,576)
Net amortization and deferral, accumulated other comprehensive (income) loss, net of tax	1,205	971
Actuarial changes in benefit obligation, accumulated other comprehensive income (loss), net of tax	(6,166)	(4,804)
Ending balance, accumulated other comprehensive (income) loss, net of tax	$ (11,370)	$ (6,409)	$ (2,576)