Summary of Significant Accounting Policies - Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Foreign currency translation	$ (403,941)	$ (394,984)
Unrecognized net actuarial loss, net of tax	(611,333)	(540,018)
Unrecognized prior service credit, net of tax	2,253	4,384
Total accumulated other comprehensive loss	$ (1,013,021)	$ (930,618)