Net Loss Per Common Share - Calculation (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Loss from continuing operations									$ (83,011,804)	$ (38,473,844)	$ (15,551,848)
Less: deemed preferred dividends on common stock											(866,569)
Net loss attributable from continuing operations to common stockholders									(83,011,804)	(38,473,844)	(16,418,417)
Loss from discontinued operations											(153,928)
Net loss attributable to common stockholders									$ (83,011,804)	$ (38,473,844)	$ (16,572,345)
Denominator:
Weighted-average basic and diluted common shares (in shares)	27,678,348	24,166,113	23,013,838	16,774,718	7,226,122	7,504,148	7,030,976	6,895,185	22,647,583	7,087,618	6,916,404
Basic and diluted net loss per common share from continuing operations									$ (3.67)	$ (5.43)	$ (2.37)
Basic and diluted net loss per common share from discontinued operations											(0.02)
Basic and diluted net loss per common share (in dollars per share)	$ (0.92)	$ (0.87)	$ (0.68)	$ (1.24)	$ (1.82)	$ (1.32)	$ (1.41)	$ (0.79)	$ (3.67)	$ (5.43)	$ (2.39)