SCHEDULE II Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Allowance, Credit Loss
Allowance for valuation and qualifying accounts
Balance at Beginning of Period	$ 40	$ 31	$ 28
Additions	9	9	11
Deductions	(13)	0	(8)
Balance at End of Period	36	40	31
Tax-Related valuation allowance
Allowance for valuation and qualifying accounts
Balance at Beginning of Period	245	159	119
Additions		86	40
Deductions	36
Balance at End of Period	$ 209	$ 245	$ 159