Stock-Based Compensation - Restricted Stock Awards (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Weighted Average Grant-Date Fair Value
Stock based compensation expenses	$ 433	$ (1,461)	$ 197	$ (526)
Restricted stock awards
Number of Shares
Unvested at beginning of period (in shares)			146,800	146,800
Forfeited (in shares)			(68,500)
Unvested at end of period (in shares)	78,300	146,800	78,300	146,800
Weighted Average Grant-Date Fair Value
Unvested at beginning of period (in dollars per share)			$ 5.70	$ 5.70
Forfeited (in dollars per share)			5.70
Unvested at end of period (in dollars per share)	$ 5.70	$ 5.70	$ 5.70	$ 5.70
Vesting period			20 months
Unvested, number of shares (in shares)	78,300	146,800	78,300	146,800
Forfeited (in shares)			(68,500)
Restricted stock awards - performance based awards
Number of Shares
Forfeited (in shares)			(68,500)
Unvested at end of period (in shares)	78,300		78,300
Weighted Average Grant-Date Fair Value
Unvested, number of shares (in shares)	78,300		78,300
Forfeited (in shares)			(68,500)
Stock based compensation expenses	$ 0	$ 0	$ (390)	$ 0