CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Citigroup’s net income	$ 3,238	$ 3,546	$ 9,826	$ 11,067
Add: Citigroup’s other comprehensive income, net change, net of taxes
Unrealized gains and losses on debt securities	1,335	(169)	1,397	793
Debt valuation adjustment (DVA)	(150)	299	(457)	(645)
Cash flow hedges	(144)	731	633	1,263
Benefit plans liability adjustment	49	312	305	72
Currency translation adjustments (CTA), net of hedges	416	(1,496)	(2,272)	(632)
Excluded component of fair value hedges	(9)	(12)	(8)	(15)
Long-duration insurance contracts	(17)	23	5	22
Citigroup’s total other comprehensive income (loss)	1,480	(312)	(397)	858
Citigroup’s total comprehensive income	4,718	3,234	9,429	11,925
Add: Other comprehensive income (loss) attributable to noncontrolling interests	40	(37)	7	9
Add: Net income (loss) attributable to noncontrolling interests	35	41	117	122
Total comprehensive income	$ 4,793	$ 3,238	$ 9,553	$ 12,056