Accounts Receivable - Schedule of Accounts Receivable (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 728	$ 680
Less: allowance for doubtful accounts	(45)	(13)
Accounts receivable, less allowance	683	667
Trade receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	570	529
Earned and unbilled receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 158	$ 151