DEBT - Long-Term Debt (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Weighted average interest rate	3.34%
Long-term debt	$ 223,080,000,000us-gaap_LongTermDebt	$ 221,116,000,000us-gaap_LongTermDebt
Weighted average interest rate including effects of derivative contracts	2.48%
Senior debt
Debt Instrument [Line Items]
Long-term debt	195,868,000,000	188,727,000,000
Subordinated debt
Debt Instrument [Line Items]
Long-term debt	25,487,000,000	28,481,000,000
Trust preferred securities
Debt Instrument [Line Items]
Long-term debt	1,725,000,000	3,908,000,000
Citigroup Inc.
Debt Instrument [Line Items]
Long-term debt	149,512,000,000	156,804,000,000
Citigroup Inc. \| Senior debt
Debt Instrument [Line Items]
Weighted average interest rate	3.85%
Long-term debt	122,323,000,000	124,857,000,000
Citigroup Inc. \| Subordinated debt
Debt Instrument [Line Items]
Weighted average interest rate	4.48%
Long-term debt	25,464,000,000	28,039,000,000
Citigroup Inc. \| Trust preferred securities
Debt Instrument [Line Items]
Weighted average interest rate	6.90%
Long-term debt	1,725,000,000	3,908,000,000
Bank
Debt Instrument [Line Items]
Long-term debt	65,146,000,000
Bank \| Senior debt
Debt Instrument [Line Items]
Weighted average interest rate	1.74%
Long-term debt	65,146,000,000	56,039,000,000
Collateralized long-term advances from Federal Home Loan Bank	19,800,000,000	14,000,000,000
Bank \| Subordinated debt
Debt Instrument [Line Items]
Weighted average interest rate	0.00%
Long-term debt	0	418,000,000
Broker-dealer
Debt Instrument [Line Items]
Long-term debt	8,422,000,000
Broker-dealer \| Senior debt
Debt Instrument [Line Items]
Weighted average interest rate	4.06%
Long-term debt	8,399,000,000	7,831,000,000
Broker-dealer \| Subordinated debt
Debt Instrument [Line Items]
Weighted average interest rate	2.07%
Long-term debt	23,000,000	24,000,000
Citigroup Funding Inc. (CFI)
Debt Instrument [Line Items]
Carrying value of Principal-Protected Trust Securities	$ 0	$ 87,000,000

Represents the weighted average interest rate at the end of the period after the effect of the derivative contract.

No definition available.

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- Definition

This element represents the carrying values of trust preferred securities.

+ References

No definition available.

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- Definition

Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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

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- Definition

Weighted average interest rate of long-term debt outstanding.

+ References

No definition available.

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