CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Millions		Total	Citigroup stockholders' equity	Preferred stock at aggregate liquidation value	Citigroup common stockholders' equity	Common stock and additional paid-in capital (APIC)	Retained earnings	Retained earnings Variable post-charge-off third-party collection costs	[1]	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)	Noncontrolling interests
Balance, beginning of period at Dec. 31, 2019				$ 17,980		$ 107,871	$ 165,369	$ 330		$ (3,076)		$ 162,623	$ (61,660)		$ (36,318)	$ 704
Increase (Decrease) in Stockholders' Equity
Issuance of new preferred stock				1,500
Redemption of preferred stock				(1,500)
Employee benefit plans						(81)							448	[2]
Preferred stock issuance costs (new issuances, net of reclassifications to retained earnings for redemptions)						2
Other (primarily reclassifications from APIC for preferred issuance costs on redemptions)						3	(4)									(2)
Common dividends	[3]						(3,226)
Preferred dividends		$ (828)					(828)
Treasury stock acquired	[4]												(2,925)
Transactions between Citigroup and the noncontrolling-interest shareholders																(6)
Citigroup’s total other comprehensive income															3,253	7
Net income before attribution of noncontrolling interests		6,756					6,738									18
Distributions paid to noncontrolling-interest shareholders																(2)
Net change in noncontrolling interests																15
Balance, end of period at Sep. 30, 2020		194,595	$ 193,876	17,980	$ 175,896	107,795	165,303						(64,137)		(33,065)	719
Balance, beginning of period at Jun. 30, 2020				17,980		107,699	163,515					163,515	(64,143)		(33,345)	680
Increase (Decrease) in Stockholders' Equity
Employee benefit plans						93							6	[2]
Other (primarily reclassifications from APIC for preferred issuance costs on redemptions)						3										(2)
Common dividends	[3]						(1,074)
Preferred dividends		(284)					(284)
Citigroup’s total other comprehensive income															280	19
Net income before attribution of noncontrolling interests		3,170					3,146									24
Distributions paid to noncontrolling-interest shareholders																(2)
Net change in noncontrolling interests																39
Balance, end of period at Sep. 30, 2020		194,595	193,876	17,980	175,896	107,795	165,303						(64,137)		(33,065)	719
Balance, beginning of period at Dec. 31, 2020		200,200		19,480		107,877	168,272					168,272	(64,129)		(32,058)	758
Increase (Decrease) in Stockholders' Equity
Issuance of new preferred stock				2,300
Redemption of preferred stock				(3,785)
Employee benefit plans						(3)							483	[2]
Preferred stock issuance costs (new issuances, net of reclassifications to retained earnings for redemptions)						40
Other (primarily reclassifications from APIC for preferred issuance costs on redemptions)						39	(40)									(21)
Common dividends	[3]						(3,176)
Preferred dividends		(811)					(811)
Treasury stock acquired	[4]												(7,600)
Transactions between Citigroup and the noncontrolling-interest shareholders																2
Citigroup’s total other comprehensive income															(4,793)	(71)
Net income before attribution of noncontrolling interests		18,846					18,779									67
Net change in noncontrolling interests																(23)
Balance, end of period at Sep. 30, 2021		201,610	200,875	17,995	182,880	107,953	183,024						(71,246)		(36,851)	735
Balance, beginning of period at Jun. 30, 2021				17,995		107,851	179,686					$ 179,686	(68,253)		(35,120)	751
Increase (Decrease) in Stockholders' Equity
Employee benefit plans						60							7	[2]
Other (primarily reclassifications from APIC for preferred issuance costs on redemptions)						42										(10)
Common dividends	[3]						(1,040)
Preferred dividends		(266)					(266)
Treasury stock acquired	[4]												(3,000)
Transactions between Citigroup and the noncontrolling-interest shareholders																1
Citigroup’s total other comprehensive income															(1,731)	(31)
Net income before attribution of noncontrolling interests		4,668					4,644									24
Net change in noncontrolling interests																(16)
Balance, end of period at Sep. 30, 2021		$ 201,610	$ 200,875	$ 17,995	$ 182,880	$ 107,953	$ 183,024						$ (71,246)		$ (36,851)	$ 735

[1] See Note 1 to the Consolidated Financial Statements 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 the first, second and third quarters of 2021 and 2020.

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