Quarterly report pursuant to Section 13 or 15(d)

Accounting Policies - Recently Adopted Accounting Pronouncements (Details)

v3.21.2
Accounting Policies - Recently Adopted Accounting Pronouncements (Details) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Dec. 31, 2019
Recently Adopted Accounting Pronouncements      
Retained earnings $ (1,122,317) $ (876,660)  
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13      
Recently Adopted Accounting Pronouncements      
Retained earnings     $ 3,200