Amounts Included in Accumulated Other Comprehensive Loss, Net of Tax (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018			$ (268,808)
Other comprehensive loss before reclassifications			(1,754)
Amounts reclassified from accumulated other comprehensive loss			5,189
Other comprehensive income	$ 7,058	$ (34,256)	3,435	$ (19,990)
Balance at June 30, 2019	(265,373)	$ (208,963)	(265,373)	$ (208,963)
Unrecognized Net Defined Benefit Plan Costs [Member]
Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018			(154,466)
Other comprehensive loss before reclassifications			0
Amounts reclassified from accumulated other comprehensive loss			5,120
Other comprehensive income			5,120
Balance at June 30, 2019	(149,346)		(149,346)
Change in Fair Value of Derivatives [Member]
Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018			(1,008)
Other comprehensive loss before reclassifications			(2,557)
Amounts reclassified from accumulated other comprehensive loss			69
Other comprehensive income			(2,488)
Balance at June 30, 2019	(3,496)		(3,496)
Foreign Currency Translation [Member]
Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018			(113,334)
Other comprehensive loss before reclassifications			803
Amounts reclassified from accumulated other comprehensive loss			0
Other comprehensive income			803
Balance at June 30, 2019	$ (112,531)		$ (112,531)