Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) by Component (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
AOCI Attributable to Parent [Roll Forward]
Beginning balance, January 1	$ 3,412,152
Other comprehensive (loss) income before reclassifications, net of tax	26,170	$ 57,020
Amounts reclassified from accumulated other comprehensive loss, net of tax	7,164	5,732
Total other comprehensive income	33,334	62,752
Ending balance, March 31	3,510,079
Pension and Other Post-Retirement Benefits [Member]
AOCI Attributable to Parent [Roll Forward]
Beginning balance, January 1	(568,957)	(609,080)
Other comprehensive (loss) income before reclassifications, net of tax	0	0
Amounts reclassified from accumulated other comprehensive loss, net of tax	7,164	5,732
Total other comprehensive income	7,164	5,732
Ending balance, March 31	(561,793)	(603,348)
Accumulated Net Investment Hedge Attributable to Parent [Member]
AOCI Attributable to Parent [Roll Forward]
Beginning balance, January 1	(17,388)	0
Other comprehensive (loss) income before reclassifications, net of tax	(16,710)	0
Amounts reclassified from accumulated other comprehensive loss, net of tax	0	0
Total other comprehensive income	(16,710)	0
Ending balance, March 31	(34,098)	0
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent [Roll Forward]
Beginning balance, January 1	(266,247)	(403,941)
Other comprehensive (loss) income before reclassifications, net of tax	42,880	57,020
Amounts reclassified from accumulated other comprehensive loss, net of tax	0	0
Total other comprehensive income	42,880	57,020
Ending balance, March 31	(223,367)	(346,921)
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent [Roll Forward]
Beginning balance, January 1	(852,592)	(1,013,021)
Ending balance, March 31	$ (819,258)	$ (950,269)