Stock-Based Compensation - Schedule of Option Activity (Detail) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, beginning balance		1,531,110
Options granted	0	281,474
Options cancelled		(34,663)
Options exercised		0
Options forfeited or expired		(456,150)
Options Outstanding, ending balance		1,321,772	1,531,110
Vested and expected to vest		1,275,332
Exercisable		871,470
Options Outstanding, beginning balance, Weighted Average Exercise Price		$ 13.57
Options granted, Weighted Average Exercise Price		12.11
Options cancelled, Weighted Average Exercise Price		21.33
Options exercised, Weighted Average Exercise Price		0
Options forfeited or expired, Weighted Average Exercise Price		19.25
Options Outstanding, ending balance, Weighted Average Exercise Price		11.10	$ 13.57
Vested and expected to vest, Weighted Average Exercise Price		11.03
Exercisable, Weighted Average Exercise Price		$ 10.01
Options Outstanding, Weighted Average Remaining Contractual Term		5 years 2 months 12 days	6 years 4 months 24 days
Vested and expected to vest, Weighted Average Remaining Contractual Term		5 years 1 month 6 days
Exercisable, Weighted Average Remaining Contractual Term		4 years 1 month 6 days
Options Outstanding, Aggregate Intrinsic Value			$ 3,979,000
Vested and expected to vest, Aggregate Intrinsic Value		$ 0
Exercisable, Aggregate Intrinsic Value		$ 0
Time Based Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, beginning balance		1,146,509
Options granted		281,474
Options cancelled		(30,759)
Options exercised		0
Options forfeited or expired		(312,413)
Options Outstanding, ending balance		1,084,810	1,146,509
Vested and expected to vest		1,042,638
Exercisable		662,891
Performance Based Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, beginning balance		384,601
Options cancelled		(3,904)
Options exercised		0
Options forfeited or expired		(143,737)
Options Outstanding, ending balance		236,962	384,601
Vested and expected to vest		232,695
Exercisable		208,579