Shelf Registration Statement and At-the-Market Offering - Additional Information (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended
	Oct. 29, 2020	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019
Registration Payment Arrangement [Line Items]
Issuance of common stock (in shares)		134	134	570
Proceeds from sales		$ 179	$ 179	$ 1,504
Offering costs		$ 9	$ 9	$ 203
Weighted average sales price (in dollars per share)		$ 1.41	$ 1.41	$ 3.00
Subsequent Event [Member]
Registration Payment Arrangement [Line Items]
Issuance of common stock (in shares)	1,900
Proceeds from sales	$ 5,994
Offering costs	$ 260
Weighted average sales price (in dollars per share)	$ 3.30
Maximum [Member]
Registration Payment Arrangement [Line Items]
Aggregate offering price		$ 50,000	$ 50,000
Compensation percentage			5.00%
Common stock aggregate offering price available for issuance		10,959	$ 10,959
JMP Securities [Member] | Maximum [Member]
Registration Payment Arrangement [Line Items]
Aggregate offering price		$ 13,000	$ 13,000