Other Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020
Other liabilities, current
Accrued compensation	$ 2,769	$ 1,560
Salary continuation payments	2,058	1,215
Restricted stock units	91	913
Deferred payroll tax liability	471	436
Accrued directors' fees	38	33
Total	5,427	4,157
Other liabilities, non-current
Salary continuation payments	827	1,145
Deferred payroll tax liability	471	505
Total	$ 1,298	$ 1,650	$ 135
Payroll tax deferred, due year one	50.00%
Payroll tax deferred, due year two	50.00%
Minimum
Other liabilities, non-current
Agreement period for postemployment benefits	12 months
Maximum
Other liabilities, non-current
Agreement period for postemployment benefits	24 months