Other Comprehensive Income (Loss) - Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Equity [Abstract]
Net income	$ 158,442	$ 185,326	$ 508,574	$ 534,720
Other comprehensive income (loss):
Foreign currency translation	38,675	11,896	118,852	50,840
Pension and other post-retirement benefit adjustments:
Recognition of prior service credit, net of tax	(212)	(222)	(637)	(666)
Recognition of actuarial loss, net of tax	5,992	4,981	17,872	14,934
Total other comprehensive income	44,455	16,655	136,087	65,108
Comprehensive income	$ 202,897	$ 201,981	$ 644,661	$ 599,828