SECURITIZATIONS AND VARIABLE INTEREST ENTITIES - Funding, Liquidity Facilities and Subordinated Interests (Details) - USD ($) $ in Billions	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Citibank Credit Card Master Trust (Master Trust)
Funding, Liquidity Facilities and Subordinated Interests
Weighted average maturity of term notes	3 years 10 months 24 days	3 years 6 months
Term notes issued to third parties	$ 5.3	$ 6.3
Term notes retained by Citigroup affiliates	1.6	1.6
Total Trust liabilities	$ 6.9	$ 7.9
Citibank OMNI Master Trust (Omni Trust)
Funding, Liquidity Facilities and Subordinated Interests
Weighted average maturity of term notes	2 years	2 years 2 months 12 days
Term notes issued to third parties	$ 1.6	$ 1.6
Term notes retained by Citigroup affiliates	4.8	4.8
Total Trust liabilities	$ 6.4	$ 6.4