Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Restricted Cash) (Details)

v3.20.4
Summary of Significant Accounting Policies (Restricted Cash) (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Restricted Cash and Cash Equivalents Items [Line Items]        
Cash and cash equivalents $ 384,565 $ 82,505 $ 289,345  
Total cash, cash equivalents and restricted cash 384,714 82,755 289,671 $ 62,263
Prepaid expense and other current assets        
Restricted Cash and Cash Equivalents Items [Line Items]        
Restricted Cash and Cash Equivalents 0 82 158  
Other non-current assets        
Restricted Cash and Cash Equivalents Items [Line Items]        
Restricted Cash and Cash Equivalents $ 149 $ 168 $ 168