Net Deferred Income Taxes (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current deferred income taxes:
Inventories	$ 0	$ 9,034
Accrued expenses	0	104,279
Derivative instruments	0	864
Total current	0	114,177
Noncurrent deferred income taxes:
Inventories	10,047	0
Accrued expenses	107,767	0
Derivative instruments	(1,112)	0
Cost in excess of net assets of business acquired	(7,956)	(13,111)
Property and equipment	(28,853)	(28,921)
Compensation payable in common stock	67,222	58,446
Net operating loss carryforwards and impairments	12,374	12,693
Valuation allowance	(6,684)	(6,097)
Total noncurrent	152,805	23,010
Total net deferred income tax asset	$ 152,805	$ 137,187