Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Insurance collateral deposits	$ 714	$ 1,233
Excess loss fund	617	943
Accumulated interest income	449	609
State collateral deposits	31	37
Materials and supplies	488	477
Other	84	0
Total	$ 2,383	$ 3,299