SUBSIDIARY GUARANTEES - Summarized Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023
Condensed Balance Sheet Statements
Cash	$ 26,917	$ 27,342	$ 25,763
Securities borrowed and purchased under resale agreements	317,970	345,700
Trading account assets	446,339	411,756
Other assets	99,569	95,963
Total assets	2,405,686	2,411,834
Securities loaned and sold under repurchase agreements	305,206	278,107
Trading account liabilities	151,259	155,345
Short-term borrowings	38,694	37,457
Long-term debt	280,321	286,619
Other liabilities	69,304	75,835
Stockholders’ equity	209,144	206,251	$ 209,422
Total liabilities and equity	2,405,686	2,411,834
Citigroup Inc.
Condensed Balance Sheet Statements
Long-term debt	163,903	162,309
Citigroup Inc. | Reportable legal entities
Condensed Balance Sheet Statements
Cash	4,013	3,011
Securities borrowed and purchased under resale agreements	0	0
Trading account assets	492	461
Advances to subsidiaries	152,756	150,845
Other assets	16,256	14,202
Total assets	394,900	387,514
Securities loaned and sold under repurchase agreements	0	0
Trading account liabilities	397	300
Short-term borrowings	0	0
Long-term debt	163,903	162,309
Advances from subsidiaries	19,307	16,724
Other liabilities	2,983	2,728
Stockholders’ equity	208,310	205,453
Total liabilities and equity	394,900	387,514
Citigroup Inc. | Reportable legal entities | Subsidiary Holding Company
Condensed Balance Sheet Statements
Investments in subsidiaries	175,038	172,125
Citigroup Inc. | Reportable legal entities | Non-Bank Subsidiaries
Condensed Balance Sheet Statements
Investments in subsidiaries	46,345	46,870
CGMHI | Reportable legal entities
Condensed Balance Sheet Statements
Cash	21,749	23,756
Securities borrowed and purchased under resale agreements	261,565	283,174
Trading account assets	305,740	273,379
Advances to subsidiaries	0	0
Other assets	162,932	167,609
Total assets	751,986	747,918
Securities loaned and sold under repurchase agreements	324,352	309,862
Trading account liabilities	103,180	111,233
Short-term borrowings	27,377	20,481
Long-term debt	179,936	184,083
Advances from subsidiaries	0	0
Other liabilities	80,973	85,079
Stockholders’ equity	36,168	37,180
Total liabilities and equity	751,986	747,918
CGMHI | Reportable legal entities | Subsidiary Holding Company
Condensed Balance Sheet Statements
Investments in subsidiaries	0	0
CGMHI | Reportable legal entities | Non-Bank Subsidiaries
Condensed Balance Sheet Statements
Investments in subsidiaries	$ 0	$ 0