General form of registration statement for all companies including face-amount certificate companies

Goodwill and Intangible Assets - Summary of Company's intangible assets (Details)

v3.21.2
Goodwill and Intangible Assets - Summary of Company's intangible assets (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]              
Gross Carrying Amount $ 186,705   $ 186,705   $ 177,120 $ 177,094  
Accumulated Amortization (69,000)   (69,000)   (55,410) (37,473)  
Total 117,705   117,705   121,710 139,621  
Amortization expense 4,600 $ 4,400 13,500 $ 13,400 17,900 17,100 $ 15,600
Trademarks and brands              
Finite-Lived Intangible Assets [Line Items]              
Gross Carrying Amount 11,736   11,736   11,690 11,690  
Accumulated Amortization (3,200)   (3,200)   (2,562) (1,718)  
Total 8,536   8,536   9,128 9,972  
Customer relationships              
Finite-Lived Intangible Assets [Line Items]              
Gross Carrying Amount 109,301   109,301   102,220 102,220  
Accumulated Amortization (34,194)   (34,194)   (27,720) (19,148)  
Total 75,107   75,107   74,500 83,072  
Developed Technology              
Finite-Lived Intangible Assets [Line Items]              
Gross Carrying Amount 65,599   65,599   63,210 63,184  
Accumulated Amortization (31,604)   (31,604)   (25,128) (16,607)  
Total $ 33,995   $ 33,995   $ 38,082 $ 46,577