Pension and other postretirement benefits - Amounts recognized in accumulated other comprehensive (income) loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan, Chance in Amounts Recognized in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance, accumulated other comprehensive (income) loss, net of tax	$ 346,959
Impact of currency translation, accumulated other comprehensive (income) loss, net of tax	62,904	$ 63,191	$ (59,758)
Ending balance, accumulated other comprehensive (income) loss, net of tax	403,522	346,959
Pension
Defined Benefit Plan, Chance in Amounts Recognized in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance, prior service cost (credit)	200	205
Net amortization and deferral, prior service cost	0	(5)
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)	200	200	205
Beginning balance, net (gain) or loss	217,939	232,335
Net amortization and deferral, net (gain) or loss	(7,900)	(8,584)
Actuarial changes in benefit obligation, net gain (loss)	10,724	(4,965)
Impact of currency translation, net (gain) or loss	(1,408)	(847)
Ending balance, net (gain) or loss	219,355	217,939	232,335
Beginning balance, deferred taxes	(77,273)	(80,657)
Net amortization and deferral, deferred taxes	1,832	1,999
Actuarial changes in benefit obligation, deferred taxes	(2,271)	1,148
Impact of currency translation, deferred taxes	365	237
Ending balance, deferred taxes	(77,347)	(77,273)	(80,657)
Beginning balance, accumulated other comprehensive (income) loss, net of tax	140,866	151,883
Net amortization and deferral, accumulated other comprehensive (income) loss, net of tax	(6,068)	(6,590)
Actuarial changes in benefit obligation, accumulated other comprehensive income (loss), net of tax	8,453	(3,817)
Impact of currency translation, accumulated other comprehensive (income) loss, net of tax	(1,043)	(610)
Ending balance, accumulated other comprehensive (income) loss, net of tax	142,208	140,866	151,883
Other Benefits
Defined Benefit Plan, Chance in Amounts Recognized in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance, prior service cost (credit)	(3,652)	(4,669)
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)	(2,635)	(3,652)	(4,669)
Beginning balance, net (gain) or loss	805	3,052
Net amortization and deferral, net (gain) or loss	241	41
Actuarial changes in benefit obligation, net gain (loss)	(6,223)	(2,288)
Ending balance, net (gain) or loss	(5,177)	805	3,052
Beginning balance, deferred taxes	271	(9)
Net amortization and deferral, deferred taxes	(287)	(243)
Actuarial changes in benefit obligation, deferred taxes	1,419	523
Ending balance, deferred taxes	1,403	271	(9)
Beginning balance, accumulated other comprehensive (income) loss, net of tax	(2,576)	(1,626)
Net amortization and deferral, accumulated other comprehensive (income) loss, net of tax	971	815
Actuarial changes in benefit obligation, accumulated other comprehensive income (loss), net of tax	(4,804)	(1,765)
Ending balance, accumulated other comprehensive (income) loss, net of tax	$ (6,409)	$ (2,576)	$ (1,626)