Loan and Security Agreement - Warrants Issued (Details) - USD ($)			1 Months Ended							3 Months Ended		9 Months Ended
	Jan. 31, 2019	Sep. 27, 2018	Sep. 30, 2019	Aug. 31, 2019	Mar. 31, 2019	Nov. 30, 2018	Dec. 31, 2017	Mar. 31, 2017	Nov. 30, 2016	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jul. 25, 2019	Dec. 31, 2018
Exercise price of warrants (in dollars per share)			$ 7.31							$ 7.31		$ 7.31			$ 6.35
Warrants exercised												(70,768)
Shares issued	3,164,015	2,966,667					1,783,587	4,304,813		942,285
Proceeds from Issuance of Long-term Debt												$ 20,000,000
Warrants issued												58,334
Amortization of debt discount												$ 471,742	$ 293,580
Warrants
Amortization of debt discount										$ 56,602	$ 24,940	155,496	$ 83,181
2019 Term Loan | Warrants
Common stock to be issued if warrants are exercised (in shares)					70,000									29,167
Exercise price of warrants (in dollars per share)					$ 8.10
Warrants issued					58,332
Fair Value Of Warrants			$ 400,000							$ 400,000		$ 400,000
Term Loan 2019, Tranche Two | Warrants
Common stock to be issued if warrants are exercised (in shares)														5,750
Exercise price of warrants (in dollars per share)														$ 25.71
Warrants issuable in future					11,668
Original Term Loan 2016
Shares issued			24,328
Original Term Loan 2016 | Warrants
Common stock to be issued if warrants are exercised (in shares)									65,228
Exercise price of warrants (in dollars per share)									$ 7.41
Term of warrants (in years)									7 years
Warrants exercised			32,614
Amended Term Loan 2016 | Warrants
Common stock to be issued if warrants are exercised (in shares)						15,750
Exercise price of warrants (in dollars per share)						$ 3.06
Term of warrants (in years)						7 years
Warrants exercised				7,875
Shares issued				6,969