Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-09, Allowance, Notes Receivable [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount	$ 9	$ 8	$ 14	$ 9
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense	2	2	9
SEC Schedule, 12-09, Valuation Allowances and Reserves, Increase (Decrease) Adjustment	0	0	0
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	(1)	(8)	(4)
SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount	65	73	77	$ 71
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense	4	6	16
SEC Schedule, 12-09, Valuation Allowances and Reserves, Increase (Decrease) Adjustment	1	(4)	(2)
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	$ (13)	$ (6)	$ (8)