Accounts Receivable - Schedule of Accounts Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 634,102	$ 553,823
Allowances for current expected credit losses and other reserves	(3,696)	(1,880)
Accounts receivable, net	630,406	551,943
Unbilled accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	163,045	157,619
Trade accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 471,057	$ 396,204