Accounts Receivable - Schedule of Accounts Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 658,556	$ 661,874
Allowances for current expected credit losses and other reserves	(1,947)	(1,822)
Accounts receivable, net	656,609	660,052
Unbilled accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	192,205	188,400
Trade accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 466,351	$ 473,474