Stock-based Compensation - Common Stock Options Activity (Detail) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Number of Shares
Options outstanding, Beginning Balance (shares)	807,949
Options granted (shares)	0
Options exercised (shares)	0
Options forfeited (shares)	(33,555)
Options expired (shares)	0
Options outstanding, Ending Balance (shares)	774,394	807,949
Exercisable at end of period (shares)	774,394
Unvested at end of period (shares)	0
Weighted Average Price per Share
Options outstanding, Beginning Balance (usd per share)	$ 8.50
Options granted (usd per share)
Options exercised (usd per share)
Options forfeited (usd per share)	$ 8.50
Options expired (usd per share)
Options outstanding, Ending Balance (usd per share)	$ 8.50	$ 8.50
Exercisable at end of period (usd per share)	8.50
Unvested at end of period (usd per share)	$ 0.00
Weighted Average Remaining Contractual Term
Options outstanding, Beginning Balance (shares)	3 years 8 months 23 days	4 years 5 months 23 days
Exercisable at end of period (shares)	3 years 8 months 23 days
Unvested at end of period (shares)	0 years
Aggregate Intrinsic Value
Options outstanding, Beginning Balance	$ 0
Options granted	0
Options exercised	0
Options forfeited	0
Options expired	0
Options outstanding, Ending Balance	0	$ 0
Exercisable at end of period	0
Unvested at end of period	$ 0