CONSOLIDATED STATEMENT OF INCOME - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues
Interest revenue	[1]	$ 70,828	$ 61,579	$ 57,988
Interest expense	[1]	24,266	16,518	12,512
Net interest revenue	[1]	46,562	45,061	45,476
Commissions and fees	[1]	11,857	12,707	11,678
Principal transactions	[1]	9,062	9,475	7,857
Administration and other fiduciary fees	[1]	3,580	3,584	3,294
Realized gains on sales of investments, net	[1]	421	778	949
Impairment losses on investments
Gross impairment losses	[1]	(132)	(63)	(620)
Net impairment losses recognized in earnings		(132)	(63)	(620)
Other revenue	[1]	1,504	902	2,163
Total non-interest revenues	[1]	26,292	27,383	25,321
Total revenues, net of interest expense	[1]	72,854	72,444	70,797
Provisions for credit losses and for benefits and claims
Provision for loan losses		7,354	7,503	6,749
Policyholder benefits and claims		101	109	204
Provision (release) for unfunded lending commitments		113	(161)	29
Total provisions for credit losses and for benefits and claims		7,568	7,451	6,982
Operating expenses
Compensation and benefits	[1]	21,154	21,181	20,970
Premises and equipment	[1]	2,324	2,453	2,542
Technology/communication	[1]	7,193	6,909	6,701
Advertising and marketing	[1]	1,545	1,608	1,632
Other operating	[1]	9,625	10,081	10,493
Total operating expenses	[1]	41,841	42,232	42,338
Income (loss) from continuing operations before income taxes		23,445	22,761	21,477
Provision for income taxes		5,357	29,388	6,444
Income (loss) from continuing operations		18,088	(6,627)	15,033
Discontinued operations
Loss from discontinued operations		(26)	(104)	(80)
Provision (benefit) for income taxes		(18)	7	(22)
Loss from discontinued operations, net of taxes		(8)	(111)	(58)
Net income (loss) before attribution of noncontrolling interests		18,080	(6,738)	14,975
Noncontrolling interests		35	60	63
Citigroup’s net income (loss)		$ 18,045	$ (6,798)	$ 14,912
Basic earnings per share
Income (loss) from continuing operations (in dollars per share)	[2]	$ 6.69	$ (2.94)	$ 4.74
Loss from discontinued operations, net of taxes (in dollars per share)	[2]	0.00	(0.04)	(0.02)
Net income (loss) (in dollars per share)	[2]	$ 6.69	$ (2.98)	$ 4.72
Weighted average common shares outstanding (in shares)		2,493.3	2,698.5	2,888.1
Diluted earnings per share
Income (loss) from continuing operations (in dollars per share)	[2]	$ 6.69	$ (2.94)	$ 4.74
Income (loss) from discontinued operations, net of taxes (in dollars per share)	[2]	0.00	(0.04)	(0.02)
Net income (loss) (in dollars per share)	[2]	$ 6.68	$ (2.98)	$ 4.72
Adjusted weighted average common shares outstanding (in shares)		2,494.8	2,698.5	2,888.3

[1] Certain prior-period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Notes 1 and 3 to the Consolidated Financial Statements.

[2] Due to rounding, earnings per share on continuing operations and discontinued operations may not sum to earnings per share on net income.