Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ (1,975,000)	$ (1,251,000)	$ (2,461,000)
State	(515,000)	(122,000)	(683,000)
Total	(2,490,000)	(1,373,000)	(3,144,000)
Deferred:
Federal	(29,000)	(219,000)	929,000
State	2,581,000	(194,000)	37,000
Total	2,552,000	(413,000)	966,000
Total income tax benefit (expense)	$ 62,000	$ (1,786,000)	$ (2,178,000)
Reconciliation of the effective income tax rate with the applicable statutory federal income tax rate
Federal tax at statutory rate (as a percent)	21.00%	21.00%	21.00%
State taxes, net of federal benefit (as a percent)	15.40%	65.80%	19.80%
Valuation allowance (as a percent)	(37.40%)	(62.40%)	(14.20%)
Other (as a percent)	0.20%	0.10%	(2.60%)
Effective income tax rate (as a percent)	(0.80%)	24.50%	24.00%
Deferred income tax assets:
Accruals not currently deductible for income taxes	$ 1,857,000	$ 1,905,000
Net operating loss carry-forwards	2,773,000	2,989,000
Total deferred income tax assets	4,630,000	4,894,000
Valuation allowance	(363,000)	(2,462,000)
Net deferred income tax assets	4,267,000	2,432,000
Deferred income tax liabilities:
Depreciation	(10,311,000)	(11,108,000)
Total deferred income tax liabilities	(10,311,000)	(11,108,000)
Net deferred income tax liability	(6,044,000)	(8,676,000)
Amounts recognized in the consolidated balance sheets:
Noncurrent deferred income tax assets	2,425,000
Noncurrent deferred income tax liabilities	(8,469,000)	(8,676,000)
Net deferred income tax liability	$ (6,044,000)	$ (8,676,000)