Stock-based Compensation - RSU (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercised (in shares)		1
Compensation costs related to unvested stock options not yet recognized		$ 1,200,000
Value of estimated forfeitures		$ 75,000
Weighted-average period of amortization		2 years 9 months 18 days
Weighted Average Grant Date Fair Value [Roll Forward]
Weighted-average grant date fair value of stock options granted (in dollars per share)	$ 0.48	$ 1.01	$ 0.48
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period of amortization		1 year 3 months 18 days
Shares [Roll Forward]
Non-vested, beginning of period (in shares)		546
Granted (in shares)		49
Vested (in shares)		(37)
Forfeited (in shares)		(207)
Non-vested, end of period (in shares)		351
Weighted Average Grant Date Fair Value [Roll Forward]
Non-vested, beginning of period (in dollars per share)		$ 2.39
Granted (in dollars per share)		3.69
Vested (in dollars per share)		2.46
Forfeited (in dollars per share)		2.55
Non-vested, end of period (in dollars per share)		$ 2.47
Unrecognized compensation expense related to restricted stock awards		$ 674,000