Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 34	$ 31	$ 25
Charges to Earnings	25	27	19
Charges to Other Accounts	(3)	(8)	1
Deductions	(15)	(16)	(14)
Balance of End of Period	41	34	31
Other reserves
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	19	22	24
Balance of End of Period	$ 19	$ 19	$ 22