BUSINESS SEGMENTS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Segment reporting information
Revenues, net of interest expense	$ 20,831	$ 20,738	$ 61,179	$ 68,230
Provision (benefit) for income taxes	1,278	698	3,430	2,546
Income (loss) from continuing operations	3,742	2,601	10,105	9,578
Pretax provisions (credits) for credit losses and for benefits and claims	3,351	5,919	9,922	21,202
Citicorp
Segment reporting information
Revenues, net of interest expense	17,705	16,289	50,557	51,300
Provision (benefit) for income taxes	1,888	1,193	4,941	4,459
Income (loss) from continuing operations	4,646	3,533	12,409	12,361
Regional Consumer Banking
Segment reporting information
Revenues, net of interest expense	8,268	8,145	24,385	24,227
Provision (benefit) for income taxes	674	470	1,940	986
Income (loss) from continuing operations	1,612	1,222	4,749	3,323
Pretax provisions (credits) for credit losses and for benefits and claims	1,200	2,400	3,700	7,800
Institutional Clients Group
Segment reporting information
Number of countries where the entity provides a broad range of banking and financial products and services	100		100
Revenues, net of interest expense	9,437	8,144	26,172	27,073
Provision (benefit) for income taxes	1,214	723	3,001	3,473
Income (loss) from continuing operations	3,034	2,311	7,660	9,038
Pretax provisions (credits) for credit losses and for benefits and claims	200	300	70	(29)
Citi Holdings
Segment reporting information
Revenues, net of interest expense	2,826	3,853	10,120	15,322
Provision (benefit) for income taxes	(441)	(597)	(853)	(2,193)
Income (loss) from continuing operations	(795)	(1,066)	(1,510)	(3,145)
Pretax provisions (credits) for credit losses and for benefits and claims	2,000	3,300	6,200	13,400
Corporate/Other
Segment reporting information
Revenues, net of interest expense	300	596	502	1,608
Provision (benefit) for income taxes	(169)	102	(658)	280
Income (loss) from continuing operations	(109)	134	(794)	362
North America
Segment reporting information
Revenues, net of interest expense	6,500	6,600	18,900	21,500
EMEA
Segment reporting information
Revenues, net of interest expense	3,600	2,900	9,800	9,700
Latin America
Segment reporting information
Revenues, net of interest expense	3,400	3,300	10,200	9,300
Asia
Segment reporting information
Revenues, net of interest expense	$ 4,300	$ 3,600	$ 11,700	$ 10,800

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- Definition

Total allowance for consumer and corporate credit losses primarily related to U.S. mortgages, revolving credit, and installment loans net of revolving credit and installment loan recoveries.

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- Definition

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses and taxes from ongoing operations before extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

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

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 29

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- Definition

The sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 45

-Subparagraph a, b

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Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

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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.

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