Components of Change in Other Assets and Liabilities Net (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Supplemental Cash Flow Elements [Abstract]
Other current and noncurrent assets	$ (32,332)	$ (9,691)
Accrued salaries, benefits and payroll taxes	(7,892)	(7,808)
Accrued insurance and other taxes	(134)	(256)
Accrued income taxes	28,047	(8,495)
Accrued pension, postretirement and postemployment benefits	11,521	11,757
Other current and noncurrent liabilities	30,740	(5,477)
Change in other assets and liabilities, net	$ 29,950	$ (19,970)