DEBT (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Short-Term Borrowings:
Commercial paper	$ 18,283,000,000	$ 11,470,000,000
Other short-term borrowings	40,524,000,000	40,557,000,000
Total short-term borrowings	58,807,000,000	52,027,000,000
Collateralized short-term advances from Federal Home Loan Bank	11,000,000,000	4,000,000,000
Significant Citibank Entities
Short-Term Borrowings:
Commercial paper	18,063,000,000	11,092,000,000
Parent
Short-Term Borrowings:
Commercial paper	$ 220,000,000	$ 378,000,000