Amounts Included in Accumulated Other Comprehensive Loss, Net of Tax (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2017			$ (188,973)
Other comprehensive loss before reclassifications			(26,651)
Amounts reclassified from accumulated other comprehensive loss			3,368
Other comprehensive loss	$ (3,293)	$ 14,876	(23,283)	$ 53,593
Balance at September 30, 2018	(212,256)	$ (170,263)	(212,256)	$ (170,263)
Unrecognized Net Defined Benefit Plan Costs [Member]
Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2017			(104,822)
Other comprehensive loss before reclassifications			(917)
Amounts reclassified from accumulated other comprehensive loss			3,358
Other comprehensive loss			2,441
Balance at September 30, 2018	(102,381)		(102,381)
Change in Fair Value of Derivatives [Member]
Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2017			(89)
Other comprehensive loss before reclassifications			663
Amounts reclassified from accumulated other comprehensive loss			10
Other comprehensive loss			673
Balance at September 30, 2018	584		584
Foreign Currency Translation [Member]
Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2017			(84,062)
Other comprehensive loss before reclassifications			(26,397)
Amounts reclassified from accumulated other comprehensive loss			0
Other comprehensive loss			(26,397)
Balance at September 30, 2018	$ (110,459)		$ (110,459)