CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Millions		Total	Variable post-charge-off third-party collection costs	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 Variable post-charge-off third-party collection costs	Retained earnings Cumulative effect of adoption	Retained earnings Adjusted balance	Treasury stock, at cost		Citigroup's accumulated other comprehensive income (loss)	Noncontrolling interests
Beginning of year balance, net of tax at Dec. 31, 2019					$ 17,980		$ 107,871	$ 165,369	$ 330	$ (3,076)	$ 162,623	$ (61,660)		$ (36,318)	$ 704
Preferred stock, beginning of year (in shares) at Dec. 31, 2019					719,000
Common stock, beginning of year (in shares) at Dec. 31, 2019							3,099,603,000
Treasury stock, beginning of year (in shares) at Dec. 31, 2019												(985,480,000)
Increase (Decrease) in Stockholders' Equity
Accounting Standards Update [Extensible Enumeration]		Accounting Standards Update 2016-13
Change in Accounting Principle, Type [Extensible Enumeration]		Change in Accounting Principle, Other [Member]
Issuance of new preferred stock					$ 3,000
Issuance of new preferred stock (in shares)					120,000
Redemption of preferred stock					$ (1,500)
Redemption of preferred stock (in shares)					(60,000)
Employee benefit plans							$ 5					$ 456	[1]
Employee benefit plans (in shares)							30,000					8,676,000	[1]
Preferred stock issuance costs (new issuances, net of reclassifications to retained earnings for redemptions)							$ (4)
Other							5	(4)							(6)
Citigroup’s net income		$ 11,047	$ (330)					11,047
Common dividends	[2]							(4,299)
Preferred dividends		(1,095)						(1,095)
Treasury stock acquired	[3]											$ (2,925)
Treasure stock acquired (in shares)	[3]											(40,740,000)
Transactions between Citigroup and the noncontrolling-interest shareholders															(4)
Net income attributable to noncontrolling-interest shareholders		11,087													40
Distributions paid to noncontrolling-interest shareholders															(2)
Other comprehensive income (loss)														4,260	26
Net change in noncontrolling interests															54
End of year balance, net of tax at Dec. 31, 2020		200,200		$ 199,442	$ 19,480	$ 179,962	$ 107,877	168,272			$ 168,272	$ (64,129)		(32,058)	758
Preferred stock, end of year (in shares) at Dec. 31, 2020					779,000
Common stock, end of year (in shares) at Dec. 31, 2020							3,099,633,000
Treasury stock, end of year (in shares) at Dec. 31, 2020												(1,017,544,000)
Increase (Decrease) in Stockholders' Equity
Total (in shares)						2,082,089,000
Issuance of new preferred stock					$ 3,300
Issuance of new preferred stock (in shares)					132,000
Redemption of preferred stock					$ (3,785)
Redemption of preferred stock (in shares)					(151,000)
Employee benefit plans							$ 85					$ 489	[1]
Employee benefit plans (in shares)							19,000					7,745,000	[1]
Preferred stock issuance costs (new issuances, net of reclassifications to retained earnings for redemptions)							$ 25
Other							47	(40)							(12)
Citigroup’s net income		21,952						21,952
Common dividends	[2]							(4,196)
Preferred dividends		(1,040)						(1,040)
Treasury stock acquired	[3]											$ (7,600)
Treasure stock acquired (in shares)	[3]											(105,498,000)
Transactions between Citigroup and the noncontrolling-interest shareholders															(10)
Net income attributable to noncontrolling-interest shareholders		22,025													73
Distributions paid to noncontrolling-interest shareholders															(10)
Other comprehensive income (loss)														(6,707)	(99)
Net change in noncontrolling interests															(58)
End of year balance, net of tax at Dec. 31, 2021		$ 202,672		201,972	$ 18,995	$ 182,977	$ 108,034	184,948				$ (71,240)		(38,765)	700
Preferred stock, end of year (in shares) at Dec. 31, 2021					760,000
Common stock, end of year (in shares) at Dec. 31, 2021							3,099,652,000
Treasury stock, end of year (in shares) at Dec. 31, 2021		(1,115,296,641)										(1,115,297,000)
Increase (Decrease) in Stockholders' Equity
Total (in shares)						1,984,355,000
Issuance of new preferred stock					$ 0
Issuance of new preferred stock (in shares)					0
Redemption of preferred stock					$ 0
Redemption of preferred stock (in shares)					0
Employee benefit plans							$ 455					$ 523	[1]
Employee benefit plans (in shares)							17,000					8,190,000	[1]
Preferred stock issuance costs (new issuances, net of reclassifications to retained earnings for redemptions)							$ 0
Other							0	1							3
Citigroup’s net income		$ 14,845						14,845
Common dividends	[2]							(4,028)
Preferred dividends		(1,032)						(1,032)
Treasury stock acquired	[3]											$ (3,250)
Treasure stock acquired (in shares)	[3]											(55,576,000)
Transactions between Citigroup and the noncontrolling-interest shareholders															(34)
Net income attributable to noncontrolling-interest shareholders		14,934													89
Distributions paid to noncontrolling-interest shareholders															(51)
Other comprehensive income (loss)														(8,297)	(58)
Net change in noncontrolling interests															(51)
End of year balance, net of tax at Dec. 31, 2022		$ 201,838		$ 201,189	$ 18,995	$ 182,194	$ 108,489	$ 194,734				$ (73,967)		$ (47,062)	$ 649
Preferred stock, end of year (in shares) at Dec. 31, 2022					760,000
Common stock, end of year (in shares) at Dec. 31, 2022							3,099,669,000
Treasury stock, end of year (in shares) at Dec. 31, 2022		(1,162,682,999)										(1,162,683,000)
Increase (Decrease) in Stockholders' Equity
Total (in shares)						1,936,986,000

[1] 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.

[2] Common dividends declared were $0.51 per share in the first, second, third and fourth quarters of 2022, 2021 and 2020.

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