CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Citigroup’s net income		$ 9,228	$ 14,845	$ 21,952
Add: Citigroup’s other comprehensive income (loss), net change, net of taxes
Unrealized gains and losses on debt securities	[1],[2]	2,254	(5,384)	(3,934)
Debt valuation adjustment (DVA)	[2],[3]	(1,551)	2,029	232
Cash flow hedges	[2]	1,116	(2,623)	(1,492)
Benefit plans liability adjustment	[2],[4]	(295)	97	1,012
CTA, net of hedges	[2]	752	(2,471)	(2,525)
Excluded component of fair value hedges	[2]	(48)	55	0
Long-duration insurance contracts	[2]	7	0	0
Citigroup’s total other comprehensive income (loss)	[2]	2,235	(8,297)	(6,707)
Total Citigroup comprehensive income		11,463	6,548	15,245
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest		84	(58)	(99)
Net Income (Loss) Attributable to Noncontrolling Interest		153	89	73
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		$ 11,700	$ 6,579	$ 15,219

[1] See Note 1.

[2] See Note 21.

[3] See Note 26.

[4] See Note 8.