Financial Statement Schedule (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowances for Doubtful Accounts and Authorized Credits
Movement in Valuation Allowances and Reserves
Balance at Beginning of Period	$ 106	$ 102	$ 81
Charged/Credited to Net Income	122	92	91
Charged to Other Account	0	0	0
Charges Utilized/Write-offs	(100)	(88)	(70)
Balance at End of Period	128	106	102
Allowance for Transaction Losses
Movement in Valuation Allowances and Reserves
Balance at Beginning of Period	28	25	23
Charged/Credited to Net Income	178	194	181
Charged to Other Account	0	0	0
Charges Utilized/Write-offs	(179)	(191)	(179)
Balance at End of Period	27	28	25
Tax Valuation Allowance
Movement in Valuation Allowances and Reserves
Balance at Beginning of Period	65	19	37
Charged/Credited to Net Income	45	33	(20)
Charged to Other Account	(1)	13	2
Charges Utilized/Write-offs	(7)	0	0
Balance at End of Period	$ 102	$ 65	$ 19