BASIS OF PRESENTATION (Details)	Mar. 31, 2012 policy
BASIS OF PRESENTATION
Minimum voting rights percentage for consolidation	50.00%
Equity method investment ownership, low end of range (as a percent)	20.00%
Equity method investment ownership, high end of range (as a percent)	50.00%
Ownership percentage, if less than this amount then income from investments is recognized when dividends are received	20.00%
Number of significant accounting policies	6

Name:	c_BasisOfPresentationDisclosureAbstract
Namespace Prefix:	c_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

This element represents the high end of range of percentage of ownership of common stock or equity participation in the investee in which the investee is accounted for under the equity method of accounting.

+ References

No definition available.

+ Details

Name:	c_EquityMethodInvestmentOwnershipPercentageHighEnd
Namespace Prefix:	c_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the low end of range of percentage of ownership of common stock or equity participation in the investee in which the investee is accounted for under the equity method of accounting.

+ References

No definition available.

+ Details

Name:	c_EquityMethodInvestmentOwnershipPercentageLowEnd
Namespace Prefix:	c_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The maximum percentage of ownership for the entity to reflect recognition of income as dividends is received.

+ References

No definition available.

+ Details

Name:	c_MaximumOwnershipPercentageIncomeRecognitionUponReceiptOfDividends
Namespace Prefix:	c_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of significant accounting policies identified by the entity.

+ References

No definition available.

+ Details

Name:	c_NumberOfSignificantAccountingPolicies
Namespace Prefix:	c_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The minimum voting rights percentage owned by the entity that triggers consolidation.

+ References

No definition available.

+ Details

Name:	c_VotingRightsPercentageTriggerConsolidation
Namespace Prefix:	c_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant