Common Stock Warrants and Common Stock Warrant Liability (Details) - $ / shares		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Outstanding at beginning		561,343	321,590
Warrants issued
Outstanding at ending		489,176	561,343
Various [Member]
Issue Date		2016 and prior
Expiration Date		Various-2020/2021
Outstanding at beginning		17,059	41,465
Warrants issued
Warrants Expired			(24,406)
Outstanding at ending		17,059	17,059
Common Stock Offering Warrants [Member]
Issue Date		November 21, 2017
Expiration Date		November 21, 2022
Exercise price (in dollars per share)	[1]	$ 19.00
Outstanding at beginning		159,092	232,875
Warrants issued
Warrants Exercised		(15,591)	(73,783)
Outstanding at ending		143,501	159,092
Dealer Manager Warrants [Member]
Issue Date		November 21, 2017
Expiration Date		November 21, 2022
Exercise price (in dollars per share)		$ 30.00
Outstanding at beginning		47,250	47,250
Warrants issued
Outstanding at ending		47,250	47,250
Warrant Reissue [Member]
Issue Date		June 20, 2018
Expiration Date		December 20, 2023
Exercise price (in dollars per share)		$ 36.40
Outstanding at beginning		56,696
Warrants issued			56,696
Outstanding at ending		56,696	56,696
Rights Offering Warrants [Member]
Issue Date		August 13, 2018
Expiration Date		August 13, 2023
Exercise price (in dollars per share)		$ 23.00
Outstanding at beginning		267,853
Warrants issued			267,853
Warrants Exercised		(64,910)
Outstanding at ending		202,943	267,853
Dealer Manager Warrants [Member]
Issue Date		August 13, 2018
Expiration Date		August 13, 2023
Exercise price (in dollars per share)		$ 34.50
Outstanding at beginning		13,393
Warrants issued			13,393
Outstanding at ending		13,393	13,393
Dealer Manager Warrants [Member]
Issue Date		July 16, 2019
Expiration Date		July 16, 2024
Exercise price (in dollars per share)		$ 33.75
Outstanding at beginning
Warrants issued		8,334
Outstanding at ending		8,334

[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.