SECURITIZATIONS AND VARIABLE INTEREST ENTITIES (Details 2) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	$ 7,930	[1]	$ 7,484	[1]
Liquidity facilities Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	3,631		3,886
Loan commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	4,299		3,598
Citicorp
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	6,920	[1]	6,287	[1]
Citicorp | Liquidity facilities Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	3,631		3,886
Citicorp | Liquidity facilities Citigroup | Asset-based financing
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	5		5
Citicorp | Liquidity facilities Citigroup | Municipal securities tender option bond trusts (TOBs)
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	3,626		3,881
Citicorp | Loan commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	3,289		2,401
Citicorp | Loan commitments Citigroup | Asset-based financing
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	2,110		1,127
Citicorp | Loan commitments Citigroup | Municipal investments
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	1,074		1,173
Citicorp | Loan commitments Citigroup | Investment funds
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	74		81
Citicorp | Loan commitments Citigroup | Other
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	31		20
Citi Holdings
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	1,010	[1]	1,197	[1]
Citi Holdings | Liquidity facilities Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount			0
Citi Holdings | Loan commitments Citigroup
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	1,010		1,197
Citi Holdings | Loan commitments Citigroup | Asset-based financing
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	90		258
Citi Holdings | Loan commitments Citigroup | Municipal investments
Funding Commitments for Significant Unconsolidated VIEs
Notional amount	$ 920		$ 939

[1] The definition of maximum exposure to loss is included in the text that follows this table.