Stockholders' Equity - Restricted Stock Units (Details)	3 Months Ended
	Mar. 31, 2017 $ / shares shares
Restricted Stock Units
Outstanding at beginning of period (in shares) | shares	530,734
Granted (in shares) | shares	151,963
Canceled/forfeited (in shares) | shares	(169,995)
Outstanding at end of period (in shares) | shares	479,402
Weighted Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 7.48
Granted (in dollars per share) | $ / shares	3.71
Canceled/forfeited (in dollars per share) | $ / shares	6.05
Outstanding at end of period (in dollars per share) | $ / shares	$ 7.15
Weighted Average Remaining Contractual Life (in years)
Outstanding at end of period	6 years 10 months 24 days
Restricted Stock Units
Restricted Stock Units
Outstanding at beginning of period (in shares) | shares	250,115
Granted (in shares) | shares	252,802
Released (in shares) | shares	(42,620)
Canceled/forfeited (in shares) | shares	(123,937)
Outstanding at end of period (in shares) | shares	336,360
Weighted Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 6.34
Granted (in dollars per share) | $ / shares	3.48
Released (in dollars per share) | $ / shares	6.00
Canceled/forfeited (in dollars per share) | $ / shares	6.30
Outstanding at end of period (in dollars per share) | $ / shares	$ 4.24
Weighted Average Remaining Contractual Life (in years)
Outstanding at end of period	3 years 3 months 18 days