DEBT - Short-Term Borrowings (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Short-Term Borrowings:
Commercial paper	$ 16,155,000,000us-gaap_CommercialPaper	$ 17,878,000,000us-gaap_CommercialPaper
Other borrowings	42,180,000,000us-gaap_OtherShortTermBorrowings	41,066,000,000us-gaap_OtherShortTermBorrowings
Total short-term borrowings	58,335,000,000us-gaap_ShortTermBorrowings	58,944,000,000us-gaap_ShortTermBorrowings
Collateralized short-term advances from Federal Home Loan Bank	11,200,000,000	11,200,000,000
Commercial paper
Short-Term Borrowings:
Commercial paper, weighted average coupon	0.23%	0.26%
Other borrowings
Short-Term Borrowings:
Commercial paper, weighted average coupon	0.53%	0.87%
Significant Citibank Entities
Short-Term Borrowings:
Commercial paper	16,085,000,000	17,677,000,000
Significant Citibank Entities \| Commercial paper
Short-Term Borrowings:
Commercial paper, weighted average coupon	0.22%	0.25%
Citigroup Inc.
Short-Term Borrowings:
Commercial paper	70,000,000	201,000,000
Total short-term borrowings	$ 1,075,000,000	$ 382,000,000
Citigroup Inc. \| Commercial paper
Short-Term Borrowings:
Commercial paper, weighted average coupon	0.95%	1.11%

Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

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Amount of advances from Federal Home Loan Bank (FHLBank) maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Sum of the carrying amounts at the balance sheet date of short-term borrowings not otherwise specified in the taxonomy having initial terms less than one year or the normal operating cycle, if longer.

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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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Weighted average interest rate of short-term debt outstanding.

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