Fair Value of Financial Instruments - Change in Value of Warrant and Derivative Liability Unobservable Inputs Financial Instrument Reconciliation (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Senior Subordinated Notes | Level 2
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of Notes	$ 117,900	$ 127,100
Derivative Liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning balance	83
Change in fair value of derivative liabilities of the Note recorded as a gain	(27)
Fair value, ending balance	$ 56