Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Operations	$ (88,084)	$ (78,643)	$ (21,639)
Foreign Operations	515	(1,871)	(119)
Loss before income tax expense (benefit)	$ (87,569)	$ (80,514)	$ (21,758)
Federal statutory rate	35.00%	35.00%	35.00%
Provision for income taxes at federal statutory rate	$ (30,649)	$ (28,180)	$ (7,615)
State taxes, net of federal benefit	113	805	37
Foreign tax rate differential	(522)	253	151
Research credits	0	0	(728)
Change in valuation allowance	18,969	8,528	0
Impairment charge	10,903	17,438	0
Acquisition costs	0	0	613
Stock compensation	230	3,384	0
Interest on Series B Preferred Stock	467	430	421
Prior year adjustment	14	518	27
Change in unrecognized tax benefits	(26)	(1,024)	875
Other	114	241	(53)
Total	$ (387)	$ 2,393	$ (6,272)