FEDERAL AND STATE INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
FEDERAL AND STATE INCOME TAXES
Operating lease liabilities	$ 5,861	$ 7,170
Accrued expenses not deductible until paid	5,479	6,105
Finance lease obligations	1,214	794
Goodwill and intangible assets	1,093	1,264
Equity incentive compensation	280	204
Revenue recognition	245	238
Net operating loss carry forwards	164	298
Allowance for doubtful accounts	228	225
Other		5
Total deferred tax assets	14,564	16,303
Deferred tax liabilities:
Tax over book depreciation	(28,577)	(30,315)
Operating leases - right of use assets	(5,755)	(7,075)
Prepaid expenses deductible when paid	(2,146)	(2,327)
Other		0
Total deferred tax liabilities	(36,478)	(39,717)
Net deferred tax liabilities	$ (21,914)	$ (23,414)