Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) by Component (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
AOCI Attributable to Parent [Roll Forward]
Beginning balance, January 1			$ 3,146,567
Other comprehensive income before reclassifications, net of tax			50,840	$ (211,868)
Amounts reclassified from accumulated other comprehensive loss, net of tax			14,268	17,493
Total other comprehensive income (loss)	$ 16,655	$ (105,085)	65,108	(194,375)
September 30, 2016	3,322,212		3,322,212
Pension and Other Post-Retirement Benefits [Member]
AOCI Attributable to Parent [Roll Forward]
Beginning balance, January 1			(535,634)	(533,213)
Other comprehensive income before reclassifications, net of tax			0	0
Amounts reclassified from accumulated other comprehensive loss, net of tax			14,268	17,493
Total other comprehensive income (loss)			14,268	17,493
September 30, 2016	(521,366)	(515,720)	(521,366)	(515,720)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent [Roll Forward]
Beginning balance, January 1			(394,984)	(186,998)
Other comprehensive income before reclassifications, net of tax			50,840	(211,868)
Amounts reclassified from accumulated other comprehensive loss, net of tax			0	0
Total other comprehensive income (loss)			50,840	(211,868)
September 30, 2016	(344,144)	(398,866)	(344,144)	(398,866)
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent [Roll Forward]
Beginning balance, January 1			(930,618)	(720,211)
September 30, 2016	$ (865,510)	$ (914,586)	$ (865,510)	$ (914,586)