Fair Value Measurements of Financial Assets and Liabilities on Recurring and Non Recurring Basis (Detail) $ in Thousands	Jun. 30, 2015 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets	$ 0
Liabilities:
Derivative instruments	(10,958)
Total fair value	(10,958)
Fair Value, Inputs, Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets	0
Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets	0
Liabilities:
Derivative instruments	(10,958)
Total fair value	(10,958)
Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets	$ 0