Equity Incentive Plans - Restricted Stock (Details) - Restricted Stock Units - USD ($)	1 Months Ended		12 Months Ended
	Feb. 28, 2018	Feb. 28, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares
Restricted stock outstanding at beginning of year (in shares)			264,361	33,334
Granted (in shares)			108,254	247,694
Vested (in shares)			(225,061)	(16,667)
Restricted stock outstanding at end of year (in shares)			147,554	264,361	33,334
Weighted Average Grant Date Fair Value
Restricted stock outstanding at beginning of year (in dollars per share)			$ 3.16	$ 5.93
Granted (in dollars per share)			3.46	2.97
Vested (in dollars per share)			3.39	5.93
Restricted stock outstanding at end of year (in dollars per share)			$ 3.03	$ 3.16	$ 5.93
Aggregate Intrinsic Value
Intrinsic value of vested shares			$ 370	$ 38
Employee
Shares
Granted (in shares)					50,000
Vested (in shares)	(16,667)	(16,667)			(16,666)
Executive officers and directors
Shares
Granted (in shares)				247,694
Executive officers
Shares
Granted (in shares)			108,254
Vesting period			1 year	2 years
Directors
Shares
Vesting period				1 year