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 Revision of Prior Period, Change in Accounting Principle, Adjustment	[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						(292)							438	[2]
Preferred stock issuance costs (new issuances, net of reclassifications to retained earnings for redemptions)						2
Common dividends	[3]						(1,081)
Preferred dividends		$ (291)					(291)
Other (primarily reclassifications from APIC for preferred issuance costs on redemptions)							(5)									10
Treasury stock acquired	[4]												(2,925)
Citigroup’s total other comprehensive income															3,797	(51)
Transactions between noncontrolling-interest shareholders and the related consolidated subsidiary																(6)
Net income before attribution of noncontrolling interests		2,530					2,536									(6)
Net change in noncontrolling interests																(53)
Balance, end of period at Mar. 31, 2020		193,326	$ 192,675	17,980	$ 174,695	107,581	163,782						(64,147)		(32,521)	651
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				(1,500)
Employee benefit plans						(175)							468	[2]
Preferred stock issuance costs (new issuances, net of reclassifications to retained earnings for redemptions)						23
Common dividends	[3]						(1,074)
Preferred dividends		(292)					(292)
Other (primarily reclassifications from APIC for preferred issuance costs on redemptions)							(32)									(9)
Treasury stock acquired													(1,600)
Citigroup’s total other comprehensive income															(2,953)	(58)
Net income before attribution of noncontrolling interests		7,975					7,942									33
Net change in noncontrolling interests																(34)
Balance, end of period at Mar. 31, 2021		$ 203,273	$ 202,549	$ 20,280	$ 182,269	$ 107,725	$ 174,816						$ (65,261)		$ (35,011)	$ 724

[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 in both of the first quarters of 2021 and 2020.

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