Components of Change in Other Assets and Liabilities Net (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Supplemental Cash Flow Elements [Abstract]
Other current and noncurrent assets	$ (3,997)	$ (4,579)
Accrued salaries, benefits and payroll taxes	413	(11,829)
Accrued insurance and other taxes	5,041	12,152
Accrued income taxes	693	13,143
Accrued pension, postretirement and postemployment benefits	(21,624)	(24,232)
Other current and noncurrent liabilities	(4,072)	4,770
Change in other assets and liabilities	$ (23,546)	$ (10,575)