Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation (Details)

v3.19.3
Basis of Presentation (Details) - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Sep. 30, 2018
Dec. 31, 2017
Accounting Policies [Abstract]        
Cash and cash equivalents $ 71,632 $ 289,345    
Restricted cash included in prepaid expenses and other current assets 82 158    
Restricted cash 168 168    
Total cash, cash equivalents and restricted cash $ 71,882 $ 289,671 $ 153,700 $ 62,115