Convertible Preferred Stock and Stock Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Feb. 07, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Warrants and Rights Note Disclosure [Abstract]
Stock warrants exercised, shares	1,277,250	0	1,277,250	267,000
Exercise price of the exercisable warrants (in dollars per share)			$ 1.21
Cash proceeds from exercise of warrants		$ 0	$ 1,545	$ 323