Stockholders' equity - Schedule of Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period			$ 362,470
Balance at end of period	$ 398,041		398,041
Currency Translation
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(169,655)	$ (169,030)	(171,235)	$ (169,575)
Other comprehensive income (loss)	(8,741)	402	(7,161)	947
Balance at end of period	(178,396)	(168,628)	(178,396)	(168,628)
Accumulated Defined Benefit Plans Adjustment | Defined Benefit Pension Plans
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(67,595)	(79,553)	(68,468)	(80,704)
Other comprehensive income (loss)	856	1,144	1,729	2,295
Balance at end of period	(66,739)	(78,409)	(66,739)	(78,409)
Accumulated Defined Benefit Plans Adjustment | OPEB
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(1,121)	(981)	(1,053)	(910)
Other comprehensive income (loss)	(63)	(64)	(131)	(135)
Balance at end of period	(1,184)	(1,045)	(1,184)	(1,045)
Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(238,371)	(249,564)	(240,756)	(251,189)
Other comprehensive income (loss)	(7,948)	1,482	(5,563)	3,107
Balance at end of period	$ (246,319)	$ (248,082)	$ (246,319)	$ (248,082)