Income Taxes (Significant components of the Companys deferred tax liabilities and assets) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Deferred tax liabilities:
Property and equipment	$ 4,802,000	$ 5,181,000
Intangible assets	20,442,000	20,765,000
Prepaid expenses	426,000	376,000
Total deferred tax liabilities	25,670,000	26,322,000
Deferred tax assets:
Allowance for doubtful accounts	89,000	64,000
Compensation	824,000	1,011,000
Other accrued liabilities	150,000	95,000
Deferred Tax Assets, Gross, Total	1,063,000	1,170,000
Less: valuation allowance	0	0
Total net deferred tax assets	1,063,000	1,170,000
Net deferred tax liabilities	24,607,000	25,152,000
Current portion of deferred tax assets	150,000	388,000
Non-current portion of deferred tax liabilities	(24,757,000)	(25,540,000)
Net deferred tax liabilities	$ (24,607,000)	$ (25,152,000)