Stock-Based Compensation - Stock Option Activity (Details) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2016 USD ($) $ / shares shares
Stock Options [Roll Forward]
Exercised (in shares)	(7,222)
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options expiration term	10 years
Total unrecognized compensation expense related to non-vested stock | $	$ 0.5
Total compensation cost not yet recognized, period for recognition	2 years 6 months
Stock Options [Roll Forward]
Beginning, outstanding (in shares)	4,551,221
Granted (in shares)	20,000
Exercised (in shares)	(7,222)
Canceled (in shares)	(1,084,571)
Forfeited (in shares)	(339,347)
Ending, outstanding (in shares)	3,140,081
Exercisable (in shares)	2,295,177
Weighted Average Exercise Price [Roll Forward]
Beginning, outstanding (in dollars per share) | $ / shares	$ 9.02
Granted (in dollars per share) | $ / shares	0.83
Exercised (in dollars per share) | $ / shares	1.40
Canceled (in dollars per share) | $ / shares	16.40
Forfeited (in dollars per share) | $ / shares	1.59
Ending, outstanding (in dollars per share) | $ / shares	7.44
Exercisable (in dollars per share) | $ / shares	$ 9.63