Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Supplemental Cash Flow Elements [Abstract]
Cash paid for interest	$ 218	$ 182
Cash paid for federal and state income taxes	182	233
Cash refund for NOL carryback under CARES Act	2,703	0
Non-cash transactions:
Change in accounts payable related to property and equipment additions	(1,237)	(1,179)
Property and equipment acquired under finance leases	1,656	4,148
Issuance of common shares in asset acquisition	$ 0	$ 392