Card Member Receivables and Card Member Loans 2 (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Aging [Abstract]
Card Member receivables Total Aging	$ 24,596	$ 20,276
Global Consumer Services Group [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Card Member receivables Total Aging	8,485	5,384
Card Member loans Total aging	641	561
Global Consumer Services Group [Member] \| Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	8,432	5,336
Global Consumer Services Group [Member] \| Card Member Receivables [Member] \| 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	17	18
Global Consumer Services Group [Member] \| Card Member Receivables [Member] \| 60 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	12	11
Global Consumer Services Group [Member] \| Card Member Receivables [Member] \| 90+ Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	24	19
Global Consumer Services Group [Member] \| Card Member Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	636	557
Global Consumer Services Group [Member] \| Card Member Loans [Member] \| 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	2	1
Global Consumer Services Group [Member] \| Card Member Loans [Member] \| 60 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	1	1
Global Consumer Services Group [Member] \| Card Member Loans [Member] \| 90+ Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	2	2
Global Commercial Services [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Card Member receivables Total Aging	16,111	14,892
Global Small Business Services [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Card Member receivables Total Aging	1,805	1,412
Global Small Business Services [Member] \| Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	1,787	1,397
Global Small Business Services [Member] \| Card Member Receivables [Member] \| 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	7	5
Global Small Business Services [Member] \| Card Member Receivables [Member] \| 60 To 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	4	4
Global Small Business Services [Member] \| Card Member Receivables [Member] \| 90+ Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	7	6
Global Corporate Payments [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Card Member receivables Total Aging	14,306	13,480
Global Corporate Payments [Member] \| Card Member Receivables [Member] \| 90+ Days Past Due [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	$ 103	$ 112

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- Definition

Financing receivables that are current.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953401-111524

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- Definition

Recorded Investment in financing receivables that are past due at the balance sheet date.

+ References

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- Definition

Amount before allowance of credit card loans issued to individuals. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(a)(4),(b))
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- Definition

Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

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