CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Millions		Total	Citigroup stockholders' equity	Preferred stock at aggregate liquidation value	Total Citigroup common stockholders’ equity	Common stock and additional paid-in capital (APIC)	Retained earnings	Retained earnings Cumulative Effect, Period of Adoption, Adjustment	[1]	Retained earnings Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury stock, at cost		Citigroup's accumulated other comprehensive income (loss)	Citigroup's accumulated other comprehensive income (loss) Cumulative Effect, Period of Adoption, Adjustment	[1]	Citigroup's accumulated other comprehensive income (loss) Cumulative Effect, Period of Adoption, Adjusted Balance	Noncontrolling interests
Balance, beginning of period at Dec. 31, 2021				$ 18,995		$ 108,034	$ 184,948	$ 0		$ 184,948	$ (71,240)		$ (38,765)	$ 0		$ (38,765)	$ 700
Increase (Decrease) in Stockholders' Equity
Issuance of new preferred stock				0
Redemption of preferred stock				0
Employee benefit plans						343					513	[2]
Preferred stock issuance costs (reclassifications to retained earnings for redemptions)						0
Other (primarily preferred stock issuance costs related to new issuances)						1	1										0
Net income before attribution of noncontrolling interests		$ 12,400					12,332										68
Common dividends	[3]						(3,025)
Preferred dividends		(794)					(794)
Treasury stock acquired	[4]										(3,250)
Transactions between Citigroup and noncontrolling-interest shareholders																	(34)
Distributions paid to noncontrolling-interest shareholders																	(51)
Citigroup’s total other comprehensive income													(9,533)				(126)
Net change in noncontrolling interests																	(143)
Balance, end of period at Sep. 30, 2022		199,117	$ 198,560	18,995	$ 179,565	108,378	193,462				(73,977)		(48,298)				557
Balance, beginning of period at Jun. 30, 2022				18,995		108,241	191,261	0		191,261	(73,988)		(45,495)	0		(45,495)	612
Increase (Decrease) in Stockholders' Equity
Issuance of new preferred stock				0
Redemption of preferred stock				0
Employee benefit plans						137					11	[2]
Preferred stock issuance costs (reclassifications to retained earnings for redemptions)						0
Other (primarily preferred stock issuance costs related to new issuances)						0	0										(2)
Net income before attribution of noncontrolling interests		3,509					3,479										30
Common dividends	[3]						(1,001)
Preferred dividends		(277)					(277)
Treasury stock acquired	[4]										0
Transactions between Citigroup and noncontrolling-interest shareholders																	0
Distributions paid to noncontrolling-interest shareholders																	(39)
Citigroup’s total other comprehensive income													(2,803)				(44)
Net change in noncontrolling interests																	(55)
Balance, end of period at Sep. 30, 2022		199,117	198,560	18,995	179,565	108,378	193,462				(73,977)		(48,298)				557
Balance, beginning of period at Dec. 31, 2022		201,838		18,995		108,489	194,734	290		195,024	(73,967)		(47,062)	27		(47,035)	649
Increase (Decrease) in Stockholders' Equity
Issuance of new preferred stock				2,750
Redemption of preferred stock				(2,250)
Employee benefit plans						296					729	[2]
Preferred stock issuance costs (reclassifications to retained earnings for redemptions)						16
Other (primarily preferred stock issuance costs related to new issuances)						(13)	(16)										8
Net income before attribution of noncontrolling interests		11,189					11,067										122
Common dividends	[3]						(3,042)
Preferred dividends		(898)					(898)
Treasury stock acquired	[4]										(1,500)
Transactions between Citigroup and noncontrolling-interest shareholders																	(14)
Distributions paid to noncontrolling-interest shareholders																	(82)
Citigroup’s total other comprehensive income													858				9
Net change in noncontrolling interests																	43
Balance, end of period at Sep. 30, 2023		210,195	209,503	19,495	190,008	108,788	202,135				(74,738)		(46,177)				692
Balance, beginning of period at Jun. 30, 2023				20,245		108,610	199,976	$ 0		$ 199,976	(74,247)		(45,865)	$ 0		$ (45,865)	703
Increase (Decrease) in Stockholders' Equity
Issuance of new preferred stock				1,500
Redemption of preferred stock				(2,250)
Employee benefit plans						170					9	[2]
Preferred stock issuance costs (reclassifications to retained earnings for redemptions)						16
Other (primarily preferred stock issuance costs related to new issuances)						(8)	(16)										0
Net income before attribution of noncontrolling interests		3,587					3,546										41
Common dividends	[3]						(1,038)
Preferred dividends		(333)					(333)
Treasury stock acquired	[4]										(500)
Transactions between Citigroup and noncontrolling-interest shareholders																	(15)
Distributions paid to noncontrolling-interest shareholders																	0
Citigroup’s total other comprehensive income													(312)				(37)
Net change in noncontrolling interests																	(11)
Balance, end of period at Sep. 30, 2023		$ 210,195	$ 209,503	$ 19,495	$ 190,008	$ 108,788	$ 202,135				$ (74,738)		$ (46,177)				$ 692

[1] See Note 1 for additional details.

[2] Includes treasury stock related to (i) certain activity on employee stock option program exercises where the employee delivers existing shares to cover the option exercise, or (ii) under Citi’s employee restricted or deferred stock programs where shares are withheld to satisfy tax requirements.

[3] Common dividends declared were $0.51 per share for each of 1Q23 and 2Q23, $0.53 per share for 3Q23 and $0.51 per share for each of 1Q22, 2Q22 and 3Q22.

[4] Primarily consists of open market purchases under Citi’s Board of Directors–approved common stock repurchase program.