CONSOLIDATED STATEMENT OF INCOME (UNAUDITED) - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024
Revenues [Abstract]
Interest income	[1]	$ 33,666	$ 36,223
Interest expense	[1]	19,654	22,716
Net interest income	[1]	14,012	13,507
Commissions and fees	[1]	2,707	2,636
Principal transactions		3,921	3,274
Administration and other fiduciary fees		1,045	1,037
Realized gains on sales of investments, net		121	115
Impairment losses on investments:
Impairment losses on investments		(58)	(30)
(Provision) releases for credit losses on AFS debt securities	[2]	0	0
Net impairment losses recognized in earnings		(58)	(30)
Other revenue		(152)	477
Total non-interest revenues		7,584	7,509
Total revenues, net of interest expense(1)	[1]	21,596	21,016
Provisions for credit losses and for benefits and claims
Provision for credit losses on loans		2,561	2,422
Provision (release) for credit losses on HTM debt securities		(5)	10
Provision for credit losses on other assets		39	4
Policyholder benefits and claims		20	27
Provision (release) for credit losses on unfunded lending commitments		108	(98)
Total provisions for credit losses and for benefits and claims	[1]	2,723	2,365
Operating expenses
Compensation and benefits	[1]	7,464	7,673
Technology/communication	[1]	2,379	2,246
Transactional and tax charges	[1]	936	904
Premises and equipment	[1]	574	585
Professional services	[1]	476	426
Advertising and marketing	[1]	250	228
Restructuring	[1]	(3)	225
Other operating	[1]	1,349	1,820
Total operating expenses	[1]	13,425	14,107
Income from continuing operations before income taxes		5,448	4,544
Provision for income taxes		1,340	1,136
Income from continuing operations		4,108	3,408
Discontinued operations
Income (loss) from discontinued operations		(1)	(1)
Benefit for income taxes		0	0
Income (loss) from discontinued operations, net of taxes		(1)	(1)
Net income before attribution to noncontrolling interests		4,107	3,407
Noncontrolling interests		43	36
Citigroup’s net income		$ 4,064	$ 3,371
Basic earnings per share
Income from continuing operations (in dollars per share)	[3]	$ 2.00	$ 1.60
Income from discontinued operations, net of taxes (in dollars per share)	[3]	0	0
Net income (in dollars per share)	[3]	$ 2.00	$ 1.59
Weighted-average common shares outstanding (in shares)		1,879.0	1,910.4
Diluted earnings per share
Income from continuing operations (in dollars per share)	[3]	$ 1.96	$ 1.58
Income (loss) from discontinued operations, net of taxes (in dollars per share)	[3]	0	0
Net income (in dollars per share)	[3]	$ 1.96	$ 1.58
Adjusted weighted-average diluted common shares outstanding (in shares)		1,919.6	1,943.2

[1]     Effective January 1, 2025, certain transaction processing fees paid by Citi, primarily to credit card networks, which were previously presented within Other operating expenses, are presented as contra-revenue within Commissions and fees reported in Non-interest revenue. Prior periods were conformed to reflect this change in presentation.

[2] In accordance with ASC 326, which requires the provision for credit losses on AFS debt securities to be included in revenue. The Total provisions for credit losses and for benefits and claims excludes the provision for credit losses on AFS debt securities, which is disclosed separately above.

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