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No definition available.

Name:	c_FairValueOptionLoansHeldAsAssetsNonaccrualStatusOr90DaysOrMorePastDue
Namespace Prefix:	c_
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Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans and long-term receivables (other than securities categorized as trading, available-for-sale or held-to-maturity) that have contractual principal amounts and for which the fair value option has been elected.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612

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This item represents the estimated amount of gains or losses included in earnings during the period attributable to changes in instrument-specific credit risk arising from loans and other receivables held as assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

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Data Type:	xbrli:monetaryItemType
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This item represents the estimated amount of gains and losses from fair value changes included in earnings that are attributable to changes in the instrument-specific credit risk of liabilities with fair values that have been significantly affected during the reporting period by changes in the instrument-specific credit risk.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Unused amount of commitments to extend credit to customers.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

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Data Type:	na
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Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_TradingAccountAssetsMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_LoansReceivableMember
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Data Type:	na
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Name:	us-gaap_EligibleItemOrGroupForFairValueOptionAxis=us-gaap_SeparatedHostFinancialInstrumentFairValueOptionMember
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Data Type:	na
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Name:	us-gaap_EligibleItemOrGroupForFairValueOptionAxis=c_CertainInvestmentsInUnallocatedPreciousMetalsMember
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Data Type:	na
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Name:	us-gaap_DerivativeByNatureAxis=us-gaap_ForwardContractsMember
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Data Type:	na
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Name:	us-gaap_PositionAxis=us-gaap_LongMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_PositionAxis=us-gaap_ShortMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_EligibleItemOrGroupForFairValueOptionAxis=us-gaap_MortgageReceivablesMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_EligibleItemOrGroupForFairValueOptionAxis=c_LoanHeldForSaleMember
Namespace Prefix:
Data Type:	na
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