Stock-based Compensation Plans and Awards - Stock Options Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Number of options outstanding
Outstanding beginning balance	3,473
Options granted	1,056
Options exercised	(15)
Options forfeited or canceled	(1,315)
Outstanding ending balance	3,199	3,473
Exercisable	861
Vested and expected to vest	2,895
Weighted average exercise price
Outstanding beginning balance, weighted average exercise price	$ 8.65
Options granted, weighted average exercise price	5.37
Options exercised, weighted average exercise price	4.39
Options forfeited or canceled , weighted average exercise price	7.40
Outstanding ending balance, weighted average exercise price	8.10	$ 8.65
Exercisable, weighted average exercise price	9.21
Vested and expected to vest, weighted average exercise price	$ 8.38
Weighted average remaining contractual term (in years)
Options outstanding, weighted average remaining contractual term	8 years 8 months 1 day	9 years 3 months 29 days
Exercisable, weighted average remaining contractual term	7 years 8 months 16 days
Vested and expected to vest, weighted average remaining contractual term	8 years 7 months 13 days
Aggregate intrinsic value
Options outstanding, aggregate intrinsic value	$ 409	$ 353
Exercisable, aggregate intrinsic value	39
Vested and expected to vest, aggregate intrinsic value	$ 313