Income Taxes (Schedule Of Deferred Income Tax Assets And Liabilities) (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Assets:
Accruals not currently deductible	$ 6,478,146	$ 5,111,242
Stock based compensation	9,100,745	9,586,372
Other	66,830	356,039
Total deferred income tax assets	15,645,721	15,053,653
Liabilities:
Excess tax over book depreciation	(30,725,471)	(39,835,025)
Goodwill	(27,799,640)	(23,341,226)
Intangible assets	(6,171,628)	(5,089,042)
Other	(2,403,131)	(1,309,849)
Total deferred income tax liability	(67,099,870)	(69,575,142)
Net deferred income taxes	$ (51,454,149)	$ (54,521,489)