BASIS OF PRESENTATION (Details 2) (USD $) In Billions, unless otherwise specified	Sep. 30, 2014 ASU No. 2013-08	Dec. 31, 2013 Effect of change in the measurement policy from annually to quarterly
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets held by consolidated investment entities	$ 3.4
Percentage of the significant plans over global pension and postretirement liabilities, which utilize quarterly measurement policy		80.00%

Represents percentage of The Significant Plans over the company's global pension and postretirement liabilities, which utilize a quarterly measurement policy.

No definition available.

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