Investment Securities (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available for Sale Securities by Type
Cost	$ 4,280,000,000	$ 4,935,000,000
Gross Unrealized Gains	154,000,000	165,000,000
Gross Unrealized Losses	(3,000,000)	(84,000,000)
Estimated Fair Value	4,431,000,000us-gaap_AvailableForSaleSecurities	5,016,000,000us-gaap_AvailableForSaleSecurities	5,614,000,000us-gaap_AvailableForSaleSecurities
State and municipal obligations [Member]
Schedule of Available for Sale Securities by Type
Cost	3,366,000,000	4,060,000,000
Gross Unrealized Gains	129,000,000	54,000,000
Gross Unrealized Losses	(2,000,000)	(79,000,000)
Estimated Fair Value	3,493,000,000	4,035,000,000	4,474,000,000
U.S. Government agency obligations [Member]
Schedule of Available for Sale Securities by Type
Cost	3,000,000	3,000,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	3,000,000	3,000,000	3,000,000
U.S. Government treasury obligations [Member]
Schedule of Available for Sale Securities by Type
Cost	346,000,000	318,000,000
Gross Unrealized Gains	4,000,000	3,000,000
Gross Unrealized Losses	0	(1,000,000)
Estimated Fair Value	350,000,000	320,000,000	338,000,000
Corporate debt securities [Member]
Schedule of Available for Sale Securities by Type
Cost	37,000,000	43,000,000
Gross Unrealized Gains	3,000,000	3,000,000
Gross Unrealized Losses	0	0
Estimated Fair Value	40,000,000	46,000,000	79,000,000
Mortgage-backed securities [Member]
Schedule of Available for Sale Securities by Type
Cost	128,000,000	160,000,000
Gross Unrealized Gains	8,000,000	5,000,000
Gross Unrealized Losses	0	(1,000,000)
Estimated Fair Value	136,000,000	164,000,000	224,000,000
Equity securities [Member]
Schedule of Available for Sale Securities by Type
Cost	0	29,000,000
Gross Unrealized Gains	1,000,000	95,000,000
Gross Unrealized Losses	0	0
Estimated Fair Value	1,000,000	124,000,000	296,000,000
Foreign government bonds and obligations [Member]
Schedule of Available for Sale Securities by Type
Cost	350,000,000	272,000,000
Gross Unrealized Gains	9,000,000	5,000,000
Gross Unrealized Losses	0	(1,000,000)
Estimated Fair Value	359,000,000	276,000,000	149,000,000
Other [Member]
Schedule of Available for Sale Securities by Type
Cost	50,000,000	50,000,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,000,000)	(2,000,000)
Estimated Fair Value	$ 49,000,000	$ 48,000,000	$ 51,000,000

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (aa)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

+ Details

Name:	us-gaap_AvailableForSaleSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesAmortizedCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_AvailableForSaleSecuritiesBalanceSheetReportedAmountsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=axp_AvailabeForSaleSecuritiesOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: