Accumulated Other Comprehensive Income - Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (245,937)	$ (197,974)
Ending Balance	(253,741)	(245,937)
Cumulative currency translation adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(141,104)	(95,828)
Other comprehensive income (loss) before reclassifications	(16,653)	(45,276)
Amounts reclassified from accumulated other comprehensive income (loss)	3,824	0
Ending Balance	(153,933)	(141,104)
Benefit plan liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(104,375)	(100,749)
Other comprehensive income (loss) before reclassifications	(10,536)	317
Amounts reclassified from accumulated other comprehensive income (loss)	14,751	(3,943)
Ending Balance	(100,160)	(104,375)
Fair value change of derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(458)	(1,397)
Other comprehensive income (loss) before reclassifications	2,858	1,839
Amounts reclassified from accumulated other comprehensive income (loss)	(2,048)	(900)
Ending Balance	352	(458)
Accumulated other comprehensive loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(245,937)	(197,974)
Other comprehensive income (loss) before reclassifications	(24,331)	(43,120)
Amounts reclassified from accumulated other comprehensive income (loss)	16,527	(4,843)
Ending Balance	$ (253,741)	$ (245,937)