Income Taxes - Components of Income Tax Benefits (Detail) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
U.S. federal
Current	$ 271,356	$ 2,432,088
Deferred	4,309,534	2,608,256
US state and local
Current	(1,464)	587,711
Deferred	1,570,368	10,320
Income tax benefit	$ 6,149,794	$ 5,638,375

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

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