CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Millions, unless otherwise specified		Total	Citigroup stockholders' equity	Preferred stock at aggregate liquidation value	Citigroup common stockholders' equity	Common stock and additional paid-in capital	Retained earnings	Treasury stock, at cost	Citigroup's accumulated other comprehensive income (loss)	Noncontrolling interest
Balance, beginning of year at Dec. 31, 2011		$ 179,573		$ 312		$ 105,833	$ 90,520	$ (1,071)	$ (17,788)	$ 1,767
Increase (Decrease) in Stockholders' Equity
Adjustment to opening balance, net of taxes	[1]						(107)
Adjusted balance, beginning of year							90,413
Citigroup's net income		5,877					5,877
Employee benefit plans						154
Common dividends	[2]						(61)
Preferred dividends		(13)					(13)
Issuance of shares pursuant to employee benefit plans								216
Treasury stock acquired	[3]							(4)
Initial origination of a noncontrolling interest										88
Transactions between Citigroup and the noncontrolling-interest shareholders										(29)
Net income attributable to noncontrolling-interest shareholders		166								166
Dividends paid to noncontrolling-interest shareholders										(4)
Other						4				(71)
Net change in Accumulated other comprehensive income (loss)		39							39
Total other comprehensive income (loss) attributable to noncontrolling interests		11								11
Net change in noncontrolling interests										161
Balance, end of period at Jun. 30, 2012		185,839	183,911	312	183,599	105,991	96,216	(859)	(17,749)	1,928
Balance, beginning of year at Dec. 31, 2012		190,997		2,562		106,421	97,809	(847)	(16,896)	1,948
Increase (Decrease) in Stockholders' Equity
Adjusted balance, beginning of year							97,809
Citigroup's net income		7,990					7,990
Employee benefit plans						510
Common dividends	[2]						(61)
Preferred dividends		(13)					(13)
Issuance of shares pursuant to employee benefit plans								(46)
Issuance of preferred stock				1,825
Redemption of preferred stock				(94)
Treasury stock acquired	[3]							(182)
Initial origination of a noncontrolling interest										5
Transactions between noncontrolling-interest shareholders and the related consolidated subsidiary										(2)
Transactions between Citigroup and the noncontrolling-interest shareholders										25
Net income attributable to noncontrolling-interest shareholders		126								126
Dividends paid to noncontrolling-interest shareholders										(4)
Other						(24)				(123)
Net change in Accumulated other comprehensive income (loss)		(3,028)							(3,028)
Total other comprehensive income (loss) attributable to noncontrolling interests		(75)								(75)
Net change in noncontrolling interests										(48)
Balance, end of period at Jun. 30, 2013		$ 197,826	$ 195,926	$ 4,293	$ 191,633	$ 106,907	$ 105,725	$ (1,075)	$ (19,924)	$ 1,900

[1] The adjustment to the opening balance for Retained earnings in 2012 represents the cumulative effect of adopting ASU 2010-26, Financial Services - Insurance (Topic 944): Accounting for Costs Associated with Acquiring or Renewing Insurance Contracts. See Note 1 to the Consolidated Financial Statements.

[2] Common dividends declared were $0.01 per share in the first and second quarter of 2013 and 2012.

[3] Consists of shares added to treasury stock related to (i) 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.