Common Stock Warrants and Common Stock Warrant Liability (Tables)

12 Months Ended

Dec. 31, 2019

Warrants and Rights Note Disclosure [Abstract]

Schedule of common stock warrant activity

							Balance										Balance								Balance
Issue	Warrant	Expiration		Exercise			December 31,										December 31,								December 31,
Date	Type	Date		Price			2017		Issued		Exercised			Expired			2018		Issued		Exercised			Expired	2019
2016 and prior	Various		Various-2020/2021		Various			41,465							(24,406	)		17,059								17,059
November 21, 2017	Common Stock Offering Warrants		November 21, 2022	$	19.00	(1)		2,32,875				(73,783	)					1,59,092				(15,591	)			1,43,501
November 21, 2017	Dealer Manager Warrants		November 21, 2022	$	30.00			47,250										47,250								47,250
June 20, 2018	Warrant Reissue		December 20, 2023	$	36.40					56,696								56,696								56,696
August 13, 2018	Rights Offering Warrants		August 13, 2023	$	23.00					2,67,853								2,67,853				(64,910	)			2,02,943
August 13, 2018	Dealer Manager Warrants		August 13, 2023	$	34.50					13,393								13,393								13,393
July 16, 2019	Dealer Manager Warrants		July 16, 2024	$	33.75															8,334						8,334
																										—
								321,590										561,343								489,176

(1) The initial exercise price of these warrants was $30.00 per share. Pursuant to antidilution price adjustment protection contained within these warrants, the initial exercise price of these warrants was adjusted downward to $29.40 on July 24, 2018, the record date of the Right's Offering and downward to $19.00 per share on August 13, 2018. These warrants were further adjusted downward from $19.00 to $7.13 and $2.1122 on January 28, 202 and March 4, 2020, respectively, in connection with separate Registered Direct Offerings. These warrants are subject to further adjustment pursuant to antidilution price adjustment protection.