Fair Value Measurements of Financial Assets and Liabilities on Recurring and Non Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets:
Impaired long-lived assets	$ 18,786
Liabilities:
Derivative instruments	(2,893)	$ (3,468)
Total fair value	15,893	(3,468)
Fair Value, Inputs, Level 2
Liabilities:
Derivative instruments	(2,893)	(3,468)
Total fair value	(2,893)	$ (3,468)
Fair Value, Inputs, Level 3
Assets:
Impaired long-lived assets	18,786
Liabilities:
Total fair value	$ 18,786