Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Supplemental Cash Flow Elements [Abstract]
Cash paid for interest	$ 220	$ 150
Cash paid for federal and state income taxes	2	21
Non-cash transactions:
Change in accounts payable related to property and equipment additions	(44)	1,129
Property and equipment acquired under finance leases	$ 2,091	$ 0