Accounts Receivable, Net (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended	12 Months Ended
		Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts		$ (60)	$ (60)	$ (60)	$ (55)	$ (60)	$ (55)
Accounts receivable, net	[1]					789	1,236
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance		60	60	$ 60	$ 55
Provision for receivables		9	8
Charge-offs		(8)	(2)
Recoveries and other		(1)	$ (1)
Credit Concentration Risk | Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Concentration risk (percentage)				7.10%	4.30%
Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Invoiced						660	980
Accrued						189	311
Allowance for doubtful accounts		(60)		$ (60)	$ (55)	(60)	(55)
Accounts receivable, net						$ 789	$ 1,236
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance		$ 60		$ 60	$ 55

[1] Allowances at June 30, 2020 determined in accordance with ASU 2016-13 adopted effective January 1, 2020 - refer to Notes 2, 8 and 9 for additional information.