Pensions and Postretirement Benefits Other than Pensions - Defined Benefit Pension and Other Postretirement Benefits Plans (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Change in benefit obligation:
Projected Benefit Obligation at beginning of year		$ 1,451,351	$ 1,562,333
Service cost - employer		9,622	11,046
Interest cost		55,692	56,055
Actuarial (gain)/loss		107,798	(80,426)
Benefits paid	$ (22,701)	(66,251)	(72,530)
Settlements		(29,390)	0
Foreign currency translation effect		(65,796)	(25,127)
Projected Benefit Obligation at December 31		1,463,026	1,451,351	$ 1,562,333
Change in plans’ assets:
Fair value of plans’ assets at beginning of year		1,146,430	1,188,673
Actual return on plans’ assets		137,021	349
Employer contribution		46,075	47,830
Benefits paid		66,251	72,530
Foreign currency translation effect		(57,011)	(17,892)
Fair value of plans’ assets at December 31		1,176,874	1,146,430	1,188,673
Funded status		(286,152)	(304,921)
Amounts recognized in the balance sheets:
Accrued liabilities		(300)	(300)
Postretirement benefits other than pensions		(247,227)	(249,650)
Pension benefits		(285,852)	(304,621)
Domestic
Change in benefit obligation:
Projected Benefit Obligation at beginning of year		1,045,467	1,105,100
Service cost - employer		9,613	11,037	9,760
Interest cost		41,595	40,202	42,842
Actuarial (gain)/loss		26,618	(52,663)
Benefits paid		(53,405)	(58,209)
Settlements		(29,390)	0
Foreign currency translation effect		0	0
Projected Benefit Obligation at December 31		1,040,498	1,045,467	1,105,100
Change in plans’ assets:
Fair value of plans’ assets at beginning of year		836,514	857,825
Actual return on plans’ assets		59,310	1,095
Employer contribution		35,312	35,803
Benefits paid		53,405	58,209
Foreign currency translation effect		0	0
Fair value of plans’ assets at December 31		848,341	836,514	857,825
Funded status		(192,157)	(208,953)
Amounts recognized in the balance sheets:
Accrued liabilities		(300)	(300)
Postretirement benefits other than pensions		0	0
Pension benefits		(191,857)	(208,653)
International
Change in benefit obligation:
Projected Benefit Obligation at beginning of year		405,884	457,233
Service cost - employer		9	9	8
Interest cost		14,097	15,853	19,620
Actuarial (gain)/loss		81,180	(27,763)
Benefits paid		(12,846)	(14,321)
Settlements		0	0
Foreign currency translation effect		(65,796)	(25,127)
Projected Benefit Obligation at December 31		422,528	405,884	457,233
Change in plans’ assets:
Fair value of plans’ assets at beginning of year		309,916	330,848
Actual return on plans’ assets		77,711	(746)
Employer contribution		10,763	12,027
Benefits paid		12,846	14,321
Foreign currency translation effect		(57,011)	(17,892)
Fair value of plans’ assets at December 31		328,533	309,916	330,848
Funded status		(93,995)	(95,968)
Amounts recognized in the balance sheets:
Accrued liabilities		0	0
Postretirement benefits other than pensions		0	0
Pension benefits		(93,995)	(95,968)
Pension Benefits - All plans
Amounts recognized in the balance sheets:
Postretirement benefits other than pensions		0	0
Other Postretirement Benefits
Change in benefit obligation:
Projected Benefit Obligation at beginning of year		265,579	278,867
Service cost - employer		2,149	2,513	2,404
Interest cost		10,819	10,320	11,305
Actuarial (gain)/loss		(5,760)	(13,726)
Benefits paid		(10,512)	(12,395)
Settlements		0	0
Foreign currency translation effect		0	0
Projected Benefit Obligation at December 31		262,275	265,579	278,867
Change in plans’ assets:
Fair value of plans’ assets at beginning of year		0	0
Actual return on plans’ assets		0	0
Employer contribution		0	0
Benefits paid		0	0
Foreign currency translation effect		0	0
Fair value of plans’ assets at December 31		0	0	$ 0
Funded status		(262,275)	(265,579)
Amounts recognized in the balance sheets:
Accrued liabilities		(15,048)	(15,929)
Postretirement benefits other than pensions		(247,227)	(249,650)
Pension benefits		$ 0	$ 0