Number of new stock issued during the period.

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Name:	us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Subsequent Events - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Apr. 23, 2020	Mar. 31, 2020	Mar. 31, 2019
Subsequent Events
Net proceeds from issuance of common stock		$ 12,690	$ 4,954
Common Stock
Subsequent Events
Number of shares issued		2,657,823	1,318,481
2019 Sales Agreement \| Common Stock \| Subsequent Event
Subsequent Events
Number of shares issued	326,558
Net proceeds from issuance of common stock	$ 1,667