Financial Instruments - Valuation of Financial Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets (liabilities), fair value	$ (36,892)	$ (67,934)
Disclosed but not carried at fair value [Member] | Term Loan [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, fair value	(22,500)
Disclosed but not carried at fair value [Member] | Senior Credit Facility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, fair value		(30,050)
Disclosed but not carried at fair value [Member] | 2017 Notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, fair value	(13,554)	(44,489)
Measured on a recurring basis [Member] | Derivative Financial Instruments (commodity) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, fair value	(838)
Assets, fair value		6,605
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets (liabilities), fair value	(838)	6,605
Significant Other Observable Inputs (Level 2) [Member] | Measured on a recurring basis [Member] | Derivative Financial Instruments (commodity) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, fair value	(838)
Assets, fair value		6,605
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets (liabilities), fair value	(36,054)	(74,539)
Significant Unobservable Inputs (Level 3) [Member] | Disclosed but not carried at fair value [Member] | Term Loan [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, fair value	(22,500)
Significant Unobservable Inputs (Level 3) [Member] | Disclosed but not carried at fair value [Member] | Senior Credit Facility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, fair value		(30,050)
Significant Unobservable Inputs (Level 3) [Member] | Disclosed but not carried at fair value [Member] | 2017 Notes [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, fair value	$ (13,554)	$ (44,489)