Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Cash paid for interest	$ 636	$ 109	$ 22
Cash paid for federal and state income taxes	234	787	459
Non-cash transactions:
Change in accounts payable related to property and equipment	(448)	1,685	70
Property and equipment acquired under capital leases	4,148	2,898	1,808
Issuance of common shares in asset acquisition (see Note 7)	392	0	0
Receivable for sale of property and equipment	$ 952	$ 0	$ 0