Loans and Accounts Receivable (Details 2) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Financing receivable recorded investment aging
Card Member receivables Total Aging	$ 54,982	$ 54,047
Card Member loans total aging	75,419	73,399
Global Consumer Services Group [Member]
Financing receivable recorded investment aging
Card Member receivables Total Aging	19,044	20,946
Card Member loans total aging	63,560	62,319
Global Consumer Services Group [Member] \| Card Member Loans [Member]
Financing receivable recorded investment aging
Current	62,718	61,491
Global Consumer Services Group [Member] \| Card Member Receivables [Member]
Financing receivable recorded investment aging
Current	18,814	20,696
Global Consumer Services Group [Member] \| 30 to 59 [Member] \| Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	230	238
Global Consumer Services Group [Member] \| 30 to 59 [Member] \| Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	71	82
Global Consumer Services Group [Member] \| 60 to 89 [Member] \| Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	178	190
Global Consumer Services Group [Member] \| 60 to 89 [Member] \| Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	45	54
Global Consumer Services Group [Member] \| 90+ days past due [Member] \| Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	434	400
Global Consumer Services Group [Member] \| 90+ days past due [Member] \| Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	114	114
Global Commercial Services [Member]
Financing receivable recorded investment aging
Card Member receivables Total Aging	35,938	33,101
Card Member loans total aging	11,859	11,080
Global Small Business Services [Member]
Financing receivable recorded investment aging
Card Member receivables Total Aging	16,669	16,119
Card Member loans total aging	11,811	11,025
Global Small Business Services [Member] \| Card Member Loans [Member]
Financing receivable recorded investment aging
Current	11,675	10,892
Global Small Business Services [Member] \| Card Member Receivables [Member]
Financing receivable recorded investment aging
Current	16,432	15,868
Global Small Business Services [Member] \| 30 to 59 [Member] \| Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	39	43
Global Small Business Services [Member] \| 30 to 59 [Member] \| Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	76	91
Global Small Business Services [Member] \| 60 to 89 [Member] \| Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	28	31
Global Small Business Services [Member] \| 60 to 89 [Member] \| Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	45	54
Global Small Business Services [Member] \| 90+ days past due [Member] \| Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	69	59
Global Small Business Services [Member] \| 90+ days past due [Member] \| Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	116	106
Global Corporate Payments [Member]
Financing receivable recorded investment aging
Card Member receivables Total Aging	19,269	16,982
Card Member loans total aging	48	55
Global Corporate Payments [Member] \| 90+ days past due [Member] \| Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	0	0
Global Corporate Payments [Member] \| 90+ days past due [Member] \| Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	$ 149	$ 148

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- Definition

Financing receivables that are current.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(a)(4),(b))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-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

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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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