Fair Value Measurements of Financial Assets and Liabilities on Recurring and Non Recurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Assets:
Impaired long-lived assets	$ 36,177	$ 5,896	$ 2,138
Liabilities:
Derivative instruments	(11,155)	(11,155)
Total fair value	(5,259)	(5,259)	2,138
Fair Value, Inputs, Level 2
Liabilities:
Derivative instruments	(11,155)	(11,155)
Total fair value	(11,155)	(11,155)
Fair Value, Inputs, Level 3
Assets:
Impaired long-lived assets		5,896	2,138
Liabilities:
Total fair value	$ 5,896	$ 5,896	$ 2,138