Equity Based Compensation - Summary of Option Activity for Stock Options With Market Condition Vesting (Detail) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares, Outstanding, Beginning Balance		600,000
Shares, Forfeited		0
Shares, Outstanding, Ending Balance	550,000	550,000	600,000
Shares, Exercisable	550,000	550,000
Shares, Expected to vest	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Outstanding, Beginning Balance		$ 8.65
Weighted Average Exercise Price, Forfeited		0.00
Weighted Average Exercise Price, Outstanding, Ending Balance	$ 8.67	8.67	$ 8.65
Weighted Average Exercise Price, Exercisable	8.67	8.67
Weighted Average Exercise Price, Expected to vest	$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Life (Yrs.), Outstanding		4 years 4 months 18 days	5 years 29 days
Weighted Average Remaining Contractual Life (Yrs.), Exercisable		4 years 4 months 18 days
Aggregate Intrinsic Value, Outstanding	$ 6,281,000	$ 6,281,000
Aggregate Intrinsic Value, Exercisable	6,281,000	6,281,000
Aggregate Intrinsic Value, Expected to vest	$ 0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value		$ 1,026
Market Based Vesting Conditions [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares, Outstanding, Beginning Balance		100,000
Shares, Forfeited	(26,666)
Shares, Outstanding, Ending Balance	73,334	73,334	100,000
Shares, Exercisable	40,000	40,000
Shares, Expected to vest	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Outstanding, Beginning Balance		$ 25.95
Weighted Average Exercise Price, Forfeited	$ 25.95
Weighted Average Exercise Price, Outstanding, Ending Balance	25.95	25.95	$ 25.95
Weighted Average Exercise Price, Exercisable	25.95	25.95
Weighted Average Exercise Price, Expected to vest	$ 0.00	$ 0.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Life (Yrs.), Outstanding	1 year 6 months 16 days		2 years 3 months 11 days
Weighted Average Remaining Contractual Life (Yrs.), Exercisable	1 year 6 months 16 days
Aggregate Intrinsic Value, Outstanding	$ 0	$ 0	$ 0
Aggregate Intrinsic Value, Exercisable	0	0
Aggregate Intrinsic Value, Expected to vest	$ 0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value		$ 76,000