Other Items (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net Interest and Other Financing [Abstract]
Interest income	$ 25	$ 32	$ 34
Interest expense(a)	(280)	(280)	(380)
Income on interest rate swaps	0	0	53
Interest capitalized	0	0	3
Total interest	(255)	(248)	(290)
Net foreign currency gains (losses)	4	9	8
Other	7	13	12
Total other	11	22	20
Net interest and other	(244)	(226)	(270)
Aggregate foreign currency gains losses [Abstract]
Net interest and other	4	9	8
Provision for income taxes	2	10	57
Aggregate foreign currency gains (losses)	$ 6	$ 19	$ 65