Stockholders' Equity - Additional Information (Details) - USD ($)			9 Months Ended
	Jul. 24, 2020	Jul. 19, 2019	Sep. 30, 2020	Dec. 31, 2019
Stock Issued During Period, Shares, New Issues	23,000,000
Common Stock, Shares Issued (in shares)			124,023,374	97,851,243
Net Proceeds From Issuance Of Common Stock			$ 1,539,000
Remaining Dollar Amount Available Under Sales Agreement			$ 19,500,000
Proceeds from Issuance of Common Stock	$ 43,700,000
Amendment To Open Sale Agreement [Member]
Maximum Sales Price from Issuance of Common Stock		$ 20,000,000
Open Market Sale Agreement [Member]
Stock Issued During Period, Shares, New Issues			434,000
Common Stock, Shares Issued (in shares)			493,000
Net Proceeds From Issuance Of Common Stock			$ 1,357,000
Remaining Dollar Amount Available Under Open Market Agreement			$ 28,400,000
Maximum Sales Price from Issuance of Common Stock		$ 30,000,000