Common Stock and Preferred Stock (Converted into Common Stock) - Shelf Registration Statement (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Jul. 31, 2019	May 31, 2018
Class of Stock [Line Items]
Maximum aggregate offering price of common stock, preferred stock, warrants, debt securities, and/or units				$ 40,000,000.0	$ 200,000,000.0
Maximum common stock shares authorized (in shares)					2,500,000
Maximum aggregate offering price of common stock under ATM agreement					$ 60,000,000.0
Commission, percent of gross proceeds from sale of common stock		3.00%
Estimated offering expenses			$ 61,000
At the Market Sales Agreement, three months ended June 30, 2020
Class of Stock [Line Items]
Shares issued (in shares)	$ 2,300,000
Stock issued (in shares)	205,083
Issuance of stock (in USD per share)	$ 11.31	$ 11.31
Proceeds from issuance of common stock	$ 2,200,000
Underwriter commissions	69,610
Estimated offering expenses	4,962
Amount available under ATM	$ 31,700,000	$ 31,700,000
At the Market Sales Agreement, six months ended June 30, 2020
Class of Stock [Line Items]
Shares issued (in shares)		$ 2,900,000
Stock issued (in shares)		283,828
Issuance of stock (in USD per share)	$ 10.31	$ 10.31
Proceeds from issuance of common stock		$ 2,800,000
Underwriter commissions		87,766
Estimated offering expenses		$ 23,996