Stock-Based Compensation (Details 3) - Restricted Stock Units (RSUs)	6 Months Ended
	Jun. 30, 2018 $ / shares shares
Number of RSUs
Non-vested balance at beginning of period (in shares) | shares	188,629
Shares granted (in shares) | shares	122,949
Shares vested (in shares) | shares	(101,607)
Shares forfeited (in shares) | shares	(11,123)
Non-vested balance at end of period (in shares) | shares	198,848
Weighted Average Exercise Price
Weighted average exercise price, non-vested balance beginning (in dollars per share) | $ / shares	$ 8.27
Shares granted - weighted average exercise price (in dollars per share) | $ / shares	3.36
Shares vested - weighted average exercise price (in dollars per share) | $ / shares	9.07
Shares forfeited - weighted average exercise price (in dollars per share) | $ / shares	7.21
Weighted average exercise price, non-vested balance ending (in dollars per share) | $ / shares	$ 4.88