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, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary of Quarterly Financial Data [Abstract]
Revenues	$ 24,207	$ 33,555	$ 29,092	$ 22,484	$ 26,614	$ 24,907	$ 20,911	$ 25,212
Cost of sales	13,787	18,455	17,227	13,052	(17,128)	(14,671)	(11,880)	(13,220)
Net (loss) income	$ 406	$ 3,480	$ 1,236	$ (21)	$ (29)	$ 1,194	$ 68	$ 1,543	$ 5,101	$ 2,776	$ 6,148
Net income per common share:
Basic	$ 0.02	$ 0.16	$ 0.06	$ 0.00	$ 0.00	$ 0.05	$ 0.00	$ 0.07	$ 0.23	$ 0.12	$ 0.26
Diluted	$ 0.02	$ 0.15	$ 0.05	$ 0.00	$ 0.00	$ 0.05	$ 0.00	$ 0.06	$ 0.23	$ 0.12	$ 0.25