Quarterly report pursuant to Section 13 or 15(d)

Presentation and Summary of Significant Accounting Policies - Additional Information (Details)

v3.20.2
Presentation and Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2019
Dec. 31, 2018
Apr. 30, 2020
Significant Accounting Policies [Line Items]              
Positive (negative) cash flows from operations     $ 1,282 $ (18,428) $ (30,117) $ (41,770)  
Net loss $ 11,013 $ 14,197 35,490 47,194 62,078 $ 61,104  
Accumulated deficit 267,979   267,979   232,489    
Proceeds from common stock offerings, net     6,517 $ 17,302      
Proceeds from the exercise of warrants     2,100        
Cash and cash equivalents 54,315   54,315   $ 44,065    
Transaction price remaining performance obligations $ 3,814   3,814        
Paycheck Protection Program [Member]              
Significant Accounting Policies [Line Items]              
Unsecured loans aggregate amount             $ 6,491
Equity Distribution Agreement [Member]              
Significant Accounting Policies [Line Items]              
Proceeds from common stock offerings, net     5,996        
Equity Distribution Agreement [Member] | Maximum [Member]              
Significant Accounting Policies [Line Items]              
Aggregate available offering price, common stock     $ 18,538