Summary of Significant Accounting Policies - Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Changes in Accumulated Other Comprehensive Loss by Component
Beginning balance	$ (930,618)
Other comprehensive income (loss) before reclassifications, net of tax	(101,700)	$ (233,655)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	19,297	23,248
Other comprehensive loss, net of tax	(82,403)	(210,407)	$ (322,556)
Ending balance	(1,013,021)	(930,618)
Pension Benefits [Member]
Changes in Accumulated Other Comprehensive Loss by Component
Beginning balance	(534,215)	(532,069)
Other comprehensive income (loss) before reclassifications, net of tax	(92,758)	(25,558)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	19,505	23,412
Other comprehensive loss, net of tax	(73,253)	(2,146)
Ending balance	(607,468)	(534,215)	(532,069)
Other Post-Retirement Benefits [Member]
Changes in Accumulated Other Comprehensive Loss by Component
Beginning balance	(1,419)	(1,144)
Other comprehensive income (loss) before reclassifications, net of tax	15	(111)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(208)	(164)
Other comprehensive loss, net of tax	(193)	(275)
Ending balance	(1,612)	(1,419)	(1,144)
Foreign Currency Translation [Member]
Changes in Accumulated Other Comprehensive Loss by Component
Beginning balance	(394,984)	(186,998)
Other comprehensive income (loss) before reclassifications, net of tax	(8,957)	(207,986)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0
Other comprehensive loss, net of tax	(8,957)	(207,986)
Ending balance	(403,941)	(394,984)	(186,998)
Accumulated Other Comprehensive Loss [Member]
Changes in Accumulated Other Comprehensive Loss by Component
Beginning balance	(930,618)	(720,211)
Other comprehensive loss, net of tax	(82,403)	(210,407)	(322,556)
Ending balance	$ (1,013,021)	$ (930,618)	$ (720,211)