Related Parties - Additional Information (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
Jun. 30, 2021
Mar. 31, 2021
Related Party Transaction [Line Items]                  
Notes issued, related parties $ 12,000   $ 12,000   $ 12,000 $ 13,000      
Property and equipment purchases     119,600 $ 65,000 96,700 46,400 $ 12,100    
Operating lease right of use assets 45,753   45,753   30,076 22,045   $ 40,022 $ 32,881
Expenses recognized for related party leases $ 900 $ 900 2,400 $ 2,600          
Property, Plant and Equipment [Member]                  
Related Party Transaction [Line Items]                  
Operating lease right of use assets         15,400 18,900      
Lease Liabilities [Member]                  
Related Party Transaction [Line Items]                  
Operating lease right of use assets         1,800 1,800      
Accounts Payable                  
Related Party Transaction [Line Items]                  
Property and equipment purchases     $ 14,700   $ 10,400 $ 6,500