Accounts Receivable - Schedule of Accounts Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 662,360	$ 661,874
Allowances for current expected credit losses and other reserves	(2,268)	(1,822)
Accounts receivable, net	660,092	660,052
Unbilled accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	183,093	188,400
Trade accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 479,267	$ 473,474