Business Segment, Geographic and Quarterly Financial Data - Summary of Quarterly Financial Data (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of Quarterly Financial Data [Abstract]
Revenues	$ 18,684	$ 24,207	$ 21,482	$ 20,190	$ 18,661	$ 33,555	$ 29,092	$ 22,484
Cost of sales	9,820	(13,787)	11,582	11,677	10,810	(18,455)	(17,227)	(13,052)
Net (loss) income	$ (17,111)	$ 406	$ 1,192	$ (720)	$ (1,086)	$ 3,480	$ 1,236	$ (21)	$ (17,725)	$ 5,101	$ 2,776
Net (loss) income per common share:
Basic	$ (0.75)	$ 0.02	$ 0.05	$ (0.03)	$ (0.05)	$ 0.16	$ 0.06	$ 0.00	$ (0.78)	$ 0.23	$ 0.12
Diluted	$ (0.75)	$ 0.02	$ 0.05	$ (0.03)	$ (0.05)	$ 0.15	$ 0.05	$ 0.00	$ (0.01)	$ 0.23	$ 0.12