FINANCIAL STATEMENT SCHEDULE (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Transaction Losses and Negative Customer Balances
Movement in Valuation Allowances and Reserves
Balance at Beginning of Period	$ 222	$ 185	$ 166
Charged/ (Credited) to Net Income	823	655	511
Charges Utilized/ (Write-offs)	(779)	(618)	(492)
Balance at End of Period	266	222	185
Allowance for Loans and Interest Receivable
Movement in Valuation Allowances and Reserves
Balance at Beginning of Period	339	233	195
Charged/ (Credited) to Net Income	274	555	385
Charges Utilized/ (Write-offs)	(484)	(449)	(347)
Balance at End of Period	$ 129	$ 339	$ 233

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

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- Definition

Amount of increase in the allowances and reserves, which consist of the valuation and qualifying accounts that are either netted against the cost of an asset or that reflect a liability established to represent expected future costs, from charges to costs and expenses.

+ References

+ Details

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- Definition

Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

+ References

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