Stockholders' Equity (Details) $ / shares in Units, $ in Thousands			1 Months Ended		12 Months Ended
	Oct. 21, 2019 shares	Sep. 28, 2018 USD ($) $ / shares shares	Oct. 31, 2019 USD ($) item $ / shares shares	May 31, 2015 shares	Dec. 31, 2019 USD ($) Vote shares	Dec. 31, 2018 USD ($) shares
Common Stock
Dividend declared or paid | $					$ 0
Shares issued (in shares)				4
Net proceeds after deducting underwriting discounts and commissions and offering costs | $						$ 65,624
Preferred stock including accrued dividends, converted into common stock		8,084,414
Initial Public Offering
Common Stock
Shares issued (in shares)		5,000,000
Price per share | $ / shares		$ 15.00
Gross proceeds | $		$ 75,000
Net proceeds after deducting underwriting discounts and commissions and offering costs | $		$ 65,600
Preferred stock including accrued dividends, converted into common stock		8,084,414
Common Stock
Common Stock
Number of votes per share | Vote					1
Shares issued (in shares)					50,000	5,000,000
Net proceeds after deducting underwriting discounts and commissions and offering costs | $						$ 5
Preferred stock including accrued dividends, converted into common stock						8,084,414
Aspire
Common Stock
Maximum amount committed to be purchased | $			$ 20,000
Term over which the purchase can be made			30 months
Threshold triggering closing price per share to issue purchase notice | $ / shares			$ 0.25
Maximum number of shares that can be purchased under purchase notice			50,000
Number of lowest closing sales price | item			3
Number of consecutive business days immediately preceding the purchase date			10 days
Maximum shares sold per business day			2,000,000
Volume-weighted average price notice, percentage of companys common stock			30.00%
Purchase price as a percentage of volume-weighted average price			97.00%
Number of commitment shares issued			104,167
Commitment fee | $			$ 600
Other transaction costs | $			$ 100
Maximum number of shares sold	2,626,165
Commitment fee percentage	19.99%
Number of commitment shares purchased					50,000
Proceeds from sale of shares | $					$ 300