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Revenue - Schedule of Utility Infrastructure Services Contracts Receivable (Details) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Disaggregation of Revenue [Line Items]    
Contracts receivable, gross $ 383,328 $ 280,470
Allowance for doubtful accounts (1,941) (2,154)
Contracts receivable, net 381,387 278,316
Billed on completed contracts and contracts in progress    
Disaggregation of Revenue [Line Items]    
Contracts receivable, gross 380,484 273,778
Other receivables    
Disaggregation of Revenue [Line Items]    
Contracts receivable, gross $ 2,844 $ 6,692