Quarterly Results of Operations Data (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenues	$ 52,457,904	$ 45,716,053	$ 42,801,745	$ 37,637,793	$ 40,119,076	$ 32,246,472	$ 31,329,468	$ 20,058,797	$ 178,613,495	$ 123,753,813	$ 76,124,109
Goodwill impairment					56,428,861	0	0	0	0	56,428,861	0
Total operating costs and expenses	47,625,240	43,666,752	41,860,659	41,598,262	96,139,307	31,992,272	33,022,146	19,610,697	174,750,913	180,764,422	56,901,470
Income (loss) from operations	4,832,664	2,049,301	941,086	(3,960,469)	(56,020,231)	254,200	(1,692,678)	448,100	3,862,582	(57,010,609)	19,222,639
Net income (loss)	$ 4,293,390	$ 1,297,931	$ (235,272)	$ (4,212,661)	$ (68,116,890)	$ 2,222,722	$ 856,595	$ 445,846	$ 1,143,388	$ (64,591,727)	$ 46,268,618
Basic net income (loss) per common stockholders (in dollars per share)	$ 0.06	$ 0.02	$ 0.00	$ (0.06)	$ (0.95)	$ 0.03	$ 0.01	$ 0.01	$ 0.02	$ (0.94)	$ 0.89
Diluted net income (loss) per common stockholders (in dollars per share)	$ 0.06	$ 0.02	$ 0.00	$ (0.06)	$ (0.95)	$ 0.03	$ 0.01	$ 0.01	$ 0.02	$ (0.94)	$ 0.80