SECURITIZATIONS AND VARIABLE INTEREST ENTITIES (Details 2) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	$ 20,732	$ 24,911
Citicorp
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	20,093	23,998
Citicorp | Citi-administered asset-backed commercial paper conduits (ABCP) | Liquidity Facilities Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	9,537
Citicorp | Third-party commercial paper conduits | Liquidity Facilities Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	298
Citicorp | Asset-based financing | Liquidity Facilities Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	5
Citicorp | Asset-based financing | Loan Commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	3,052
Citicorp | Municipal securities tender option bond trusts (TOBs) | Liquidity Facilities Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	5,258
Citicorp | Municipal investments | Loan Commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	1,745
Citicorp | Investment funds | Loan Commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	63
Citicorp | Other. | Loan Commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	135
Citicorp | Liquidity Facilities Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	15,098
Citicorp | Loan Commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	4,995
Citi Holdings
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	639	913
Citi Holdings | Collateralized loan obligations (CLOs) | Loan Commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	7
Citi Holdings | Asset-based financing | Loan Commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	399
Citi Holdings | Municipal investments | Loan Commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	98
Citi Holdings | Other. | Loan Commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	135
Citi Holdings | Loan Commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	639
Liquidity Facilities Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	15,098
Loan Commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	$ 5,634