Components of Change in Other Assets and Liabilities Net (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Supplemental Cash Flow Elements [Abstract]
Other current and noncurrent assets	$ (5,501)	$ (6,139)
Accrued salaries, benefits and payroll taxes	(13,794)	(755)
Accrued insurance and other taxes	(1,278)	3,911
Accrued income taxes	(19,902)	16,678
Accrued pension, postretirement and postemployment benefits	16,283	4,281
Other current and noncurrent liabilities	(4,878)	(389)
Change in other assets and liabilities	$ (29,070)	$ 17,587