Supplementary Quarterly Financial Information (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended								12 Months Ended
	May. 30, 2014	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Revenues		$ 15,420	$ 11,309	$ 13,590	$ 10,849	$ 14,706	$ 9,658	$ 4,432	$ 0	$ 51,168	$ 28,796	$ 19
Gross profit (loss)		8,191	4,537	6,689	5,281	7,954	4,126	(577)	0	24,698	11,503	15
Loss from operations		(4,957)	(4,877)	(2,265)	(4,572)	(2,345)	(8,022)	(8,522)	(4,645)	(16,671)	(23,534)	(20,964)
Net loss		$ (4,910)	$ (4,416)	$ (2,152)	$ (4,862)	$ (2,370)	$ (6,917)	$ (4,638)	$ (5,995)	$ (16,340)	$ (19,920)	$ (15,622)
Net loss per share (basic and diluted) (in dollars per share)		$ (0.28)	$ (0.26)	$ (0.16)	$ (0.27)	$ (0.17)	$ (0.82)	$ (0.94)	$ (1.26)	$ (0.97)	$ (2.23)	$ (6.95)
Bargain purchase gain										$ 0	$ 3,473	$ 0
CTRM Business
Business Acquisition [Line Items]
Bargain purchase gain	$ 3,473							$ 3,500