SUBSIDIARY GUARANTEES - Summarized Income Statement (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Condensed Income Statements
Revenues, net of interest expense	$ 20,315	$ 20,139	$ 61,558	$ 61,022
Total operating expenses	13,250	13,511	40,798	40,370
Provision for credit losses	2,382	1,816	7,163	5,314
Income from continuing operations before income taxes	4,390	4,788	13,244	15,013
Provision (benefits) for income taxes	1,116	1,203	3,299	3,824
Citigroup’s net income	$ 3,238	$ 3,546	9,826	$ 11,067
Citigroup Inc. | Reportable legal entities
Condensed Income Statements
Revenues, net of interest expense			2,454
Total operating expenses			222
Provision for credit losses			0
Equity in undistributed income of subsidiaries			7,067
Income from continuing operations before income taxes			9,299
Provision (benefits) for income taxes			(527)
Citigroup’s net income			9,826
CGMHI | Reportable legal entities
Condensed Income Statements
Revenues, net of interest expense			8,870
Total operating expenses			9,300
Provision for credit losses			15
Equity in undistributed income of subsidiaries			0
Income from continuing operations before income taxes			(445)
Provision (benefits) for income taxes			156
Citigroup’s net income			$ (601)