Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 15,011	$ 12,715	$ 9,934	$ 6,139	$ 10,377	$ 7,633	$ 5,702	$ 5,409	$ 43,799	$ 29,121	$ 9,611
Gross profit	14,008	11,951	9,017	5,375	9,608	7,123	5,296	4,883	40,351	26,910	8,666
Loss from continuing operations, net of income taxes	(63)	(3,273)	(6,803)	(9,561)	(3,094)	(4,114)	(6,698)	(9,944)	(19,700)	(23,850)	(29,176)
Total income (loss) from discontinued operations, net of income taxes	(844)	15,567	4,503	2,701	2,693	497	843	(1,130)	21,927	2,903	(14,054)
Net income (loss)	$ (907)	$ 12,294	$ (2,300)	$ (6,860)	$ (401)	$ (3,617)	$ (5,855)	$ (11,074)	$ 2,227	$ (20,947)	$ (43,230)
Net income (loss) per share - basic and diluted
Loss from continuing operations, net of income taxes (usd per share)	$ 0.00	$ (0.06)	$ (0.14)	$ (0.19)	$ (0.06)	$ (0.08)	$ (0.13)	$ (0.19)	$ (0.39)	$ (0.46)	$ (0.57)
Income (loss) from discontinued operations, net of income taxes (usd per share)	(0.02)	0.30	0.09	0.05	0.05	0.01	0.02	(0.02)	0.43	0.06	(0.27)
Net income (loss) (usd per share)	$ (0.02)	$ 0.24	$ (0.05)	$ (0.14)	$ (0.01)	$ (0.07)	$ (0.11)	$ (0.21)	$ 0.04	$ (0.40)	$ (0.84)
Weighted-average number of shares of common stock outstanding:
Basic and diluted weighted-average number of shares outstanding (shares)	51,195,402	50,642,344	50,205,913	49,998,547	51,644,295	52,473,601	52,633,054	52,372,857	50,511,366	52,279,738	51,684,397