Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 19, 2021	Mar. 23, 2020	Jan. 28, 2020	Nov. 06, 2019	Oct. 25, 2019	Mar. 12, 2019	Jul. 03, 2018	Nov. 27, 2017
Subsequent Events [Abstract]
Issuance of common stock, net (in shares)			201,546	40,637	19,195
Gross proceeds from public stock offering			$ 9,700	$ 1,360	$ 660
Net proceeds from public stock offering			$ 8,600
Exercise price of warrants (in dollars per share)		$ 11.18	$ 16.50	$ 29.83	$ 42.30
Subsequent Event [Member]
Subsequent Events [Abstract]
Issuance of common stock, net (in shares)	3,795,816
Gross proceeds from public stock offering	$ 20,900
Net proceeds from public stock offering	$ 19,000
March 2020 Offering [Member]
Subsequent Events [Abstract]
Issuance of common stock, net (in shares)		138,715
Gross proceeds from public stock offering		$ 1,200
Net proceeds from public stock offering		$ 1,000
Exercise price of warrants (in dollars per share)		$ 9.00
March 2021 Offering [Member] | Subsequent Event [Member]
Subsequent Events [Abstract]
Exercise price of warrants (in dollars per share)	$ 5.50
Series F Convertible Preferred Stock [Member]
Subsequent Events [Abstract]
Conversion price (in dollars per share)		$ 9.00	$ 16.50	$ 29.83	$ 42.30	$ 157.50	$ 890.40	$ 1,890.00
Series F Convertible Preferred Stock [Member] | Subsequent Event [Member]
Subsequent Events [Abstract]
Conversion price (in dollars per share)	$ 5.50