Stock Purchase Warrants - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Equity [Abstract]
Weighted average remaining lives	3 years 9 months 8 days
Change in fair value measurements	$ 0	$ 0	$ (3,717)