Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Cash paid for interest	$ 746	$ 444	$ 636
Cash paid for federal and state income taxes	2,251	418	234
Cash refund for NOL carryback under CARES Act	3,712	2,703	0
Non-cash transactions:
Change in accounts payable related to property and equipment	0	(1,237)	(448)
Property and equipment acquired under capital leases	2,083	11,412	4,148
Issuance of common shares in asset acquisition (see Note 6)	0	0	392
Receivable for sale of property and equipment	$ 0	$ 0	$ 952