Quarterly report pursuant to Section 13 or 15(d)

Capital Structure - Common Stock (Details)

Capital Structure - Common Stock (Details) $ / shares in Units, $ in Millions							1 Months Ended		3 Months Ended		12 Months Ended
	Mar. 17, 2020 USD ($) $ / shares shares	Feb. 06, 2020 USD ($) $ / shares shares	Feb. 03, 2020 shares	Sep. 04, 2019 USD ($) day $ / shares shares	Mar. 08, 2019 USD ($) $ / shares shares	Dec. 26, 2018 shares	Mar. 31, 2020 USD ($) class_of_stock $ / shares shares	Feb. 29, 2020 USD ($) $ / shares shares	Mar. 31, 2020 Vote class_of_stock $ / shares shares	Dec. 31, 2018 shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2019 $ / shares shares	Dec. 27, 2018 $ / shares shares	Dec. 31, 2014 shares
Common Stock
Number of classes of stock authorized to issue \| class_of_stock							2		2
Number of shares of capital stock authorized to issue (in shares)							205,000,000		205,000,000
Common stock, shares authorized (in shares)							200,000,000		200,000,000			200,000,000
Preferred stock, shares authorized (in shares)							5,000,000		5,000,000			5,000,000
Common stock, par value (in dollars per share) \| $ / shares							$ 0.001		$ 0.001			$ 0.001
Preferred stock, par value per share (in dollars per share) \| $ / shares							$ 0.001		$ 0.001			$ 0.001
Number of shares available under warrant (in shares)													4,000,000
Exercise price per share (in dollars per share) \| $ / shares													$ 12.50
Warrants outstanding term													5 years 6 months
Preferred stock, shares outstanding (in shares)							1,257,143		1,257,143			2,857,143
Number of redemption or sinking fund provisions \| class_of_stock									0
Sale of stock (in shares)					363,637
Purchase price (in dollars per share) \| $ / shares					$ 5.50
Preferred Stock
Common Stock
Conversion of preferred stock to common stock (in shares)									(1,600,000)
Common Stock
Common Stock
Number of shares available under warrant (in shares)														22,328
Conversion of preferred stock to common stock (in shares)									8,000,000
Series B Preferred Stock \| Preferred Stock
Common Stock
Preferred stock conversion ratio						0.20			0.20	0.20
Number of shares available under warrant (in shares)														625,208
Shares converted (in shares)									1,600,000
Common Stock
Common Stock
Number of redemption or sinking fund provisions \| class_of_stock									0
Number of votes per share \| Vote									1
Number of preemptive, conversion or subscription rights \| class_of_stock									0
Private Placement
Common Stock
Number of shares available under warrant (in shares)													14,285,714
Exercise price per share (in dollars per share) \| $ / shares													$ 0.40
Proceeds from warrant exercises \| $											$ 5.7
Private Placement \| Series B Preferred Stock \| Preferred Stock
Common Stock
Preferred stock, shares authorized (in shares)						2,857,143				2,857,143	2,857,143		2,857,143
Preferred stock, par value per share (in dollars per share) \| $ / shares													$ 2.00
Armistice Purchase Agreement
Common Stock
Sale of stock (in shares)	1,951,219			1,200,000			1,951,219
Purchase price (in dollars per share) \| $ / shares	$ 2.05			$ 3.132			$ 2.05		$ 2.05
Net proceeds \| $	$ 3.9			$ 3.7			$ 3.9
Trading days \| day				5
Registered Direct Offering
Common Stock
Sale of stock (in shares)		1,306,282						1,306,282
Purchase price (in dollars per share) \| $ / shares		$ 3.98						$ 3.98
Bought Deal
Common Stock
Sale of stock (in shares)					1,818,182
Net proceeds \| $					$ 9.0
Armistice \| Registered Direct Offering \| Common Stock
Common Stock
Sale of stock (in shares)		1,256,282						1,256,282
Net proceeds \| $		$ 5.0						$ 5.0
Aevi
Common Stock
Shares issued (in shares)			3,900,000