CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - Condensed Consolidating Statements of Income and Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Revenues
Dividends from subsidiaries		$ 0	$ 0
Interest revenue		13,151	12,534
Interest revenue—intercompany		0	0
Interest expense		2,280	2,028
Interest expense—intercompany		0	0
Net interest income		10,871	10,506
Commissions and fees		2,568	3,670
Commissions and fees—intercompany		0	0
Principal transactions		4,590	3,913
Principal transactions—intercompany		0	0
Other revenue		1,157	1,578
Other revenue—intercompany		0	0
Total non-interest revenues		8,315	9,161
Total revenues, net of interest expense		19,186	19,667
Total provisions for credit losses and for benefits and claims	[1]	755	(2,055)
Operating expenses
Compensation and benefits		6,820	6,001
Compensation and benefits—intercompany		0	0
Other operating		6,345	5,412
Other operating—intercompany		0	0
Total operating expenses		13,165	11,413
Equity in undistributed income of subsidiaries		0	0
Income (loss) from continuing operations before income taxes		5,266	10,309
Provision (benefits) for income taxes		941	2,332
Income (loss) from continuing operations		4,325	7,977
Income (loss) from discontinued operations, net of taxes		(2)	(2)
Net income (loss) before attribution of noncontrolling interests		4,323	7,975
Noncontrolling interests		17	33
Citigroup’s net income		4,306	7,942
Comprehensive income
Add: Other comprehensive income (loss)	[2]	(4,820)	(2,953)
Total Citigroup comprehensive income (loss)		(514)	4,989
Add: Other comprehensive income (loss) attributable to noncontrolling interests		(29)	(58)
Add: Net income (loss) attributable to noncontrolling interests		17	33
Total comprehensive income (loss)		(526)	4,964
Reportable legal entities | Citigroup parent company
Revenues
Dividends from subsidiaries		250	100
Interest revenue		0	0
Interest revenue—intercompany		902	958
Interest expense		1,179	1,212
Interest expense—intercompany		90	84
Net interest income		(367)	(338)
Commissions and fees		0	0
Commissions and fees—intercompany		0	(26)
Principal transactions		1,862	1,769
Principal transactions—intercompany		(1,849)	(1,878)
Other revenue		69	55
Other revenue—intercompany		(57)	(64)
Total non-interest revenues		25	(144)
Total revenues, net of interest expense		(92)	(382)
Total provisions for credit losses and for benefits and claims		0	0
Operating expenses
Compensation and benefits		0	28
Compensation and benefits—intercompany		11	24
Other operating		24	11
Other operating—intercompany		3	3
Total operating expenses		38	66
Equity in undistributed income of subsidiaries		4,134	8,173
Income (loss) from continuing operations before income taxes		4,004	7,725
Provision (benefits) for income taxes		(302)	(217)
Income (loss) from continuing operations		4,306	7,942
Income (loss) from discontinued operations, net of taxes		0	0
Net income (loss) before attribution of noncontrolling interests		4,306	7,942
Noncontrolling interests		0	0
Citigroup’s net income		4,306	7,942
Comprehensive income
Add: Other comprehensive income (loss)		(4,820)	(2,953)
Total Citigroup comprehensive income (loss)		(514)	4,989
Add: Other comprehensive income (loss) attributable to noncontrolling interests		0	0
Add: Net income (loss) attributable to noncontrolling interests		0	0
Total comprehensive income (loss)		(514)	4,989
Reportable legal entities | CGMHI
Revenues
Dividends from subsidiaries		0	0
Interest revenue		762	971
Interest revenue—intercompany		139	145
Interest expense		194	223
Interest expense—intercompany		354	329
Net interest income		353	564
Commissions and fees		1,361	2,161
Commissions and fees—intercompany		84	47
Principal transactions		1,597	5,658
Principal transactions—intercompany		(88)	(4,238)
Other revenue		158	103
Other revenue—intercompany		(18)	(20)
Total non-interest revenues		3,094	3,711
Total revenues, net of interest expense		3,447	4,275
Total provisions for credit losses and for benefits and claims		(1)	4
Operating expenses
Compensation and benefits		1,512	1,334
Compensation and benefits—intercompany		0	0
Other operating		656	642
Other operating—intercompany		754	680
Total operating expenses		2,922	2,656
Equity in undistributed income of subsidiaries		0	0
Income (loss) from continuing operations before income taxes		526	1,615
Provision (benefits) for income taxes		(216)	452
Income (loss) from continuing operations		742	1,163
Income (loss) from discontinued operations, net of taxes		0	0
Net income (loss) before attribution of noncontrolling interests		742	1,163
Noncontrolling interests		0	0
Citigroup’s net income		742	1,163
Comprehensive income
Add: Other comprehensive income (loss)		449	(50)
Total Citigroup comprehensive income (loss)		1,191	1,113
Add: Other comprehensive income (loss) attributable to noncontrolling interests		0	0
Add: Net income (loss) attributable to noncontrolling interests		0	0
Total comprehensive income (loss)		1,191	1,113
Reportable legal entities | Other Citigroup subsidiaries and eliminations
Revenues
Dividends from subsidiaries		0	0
Interest revenue		12,389	11,563
Interest revenue—intercompany		(1,041)	(1,103)
Interest expense		907	593
Interest expense—intercompany		(444)	(413)
Net interest income		10,885	10,280
Commissions and fees		1,207	1,509
Commissions and fees—intercompany		(84)	(21)
Principal transactions		1,131	(3,514)
Principal transactions—intercompany		1,937	6,116
Other revenue		930	1,420
Other revenue—intercompany		75	84
Total non-interest revenues		5,196	5,594
Total revenues, net of interest expense		16,081	15,874
Total provisions for credit losses and for benefits and claims		756	(2,059)
Operating expenses
Compensation and benefits		5,308	4,639
Compensation and benefits—intercompany		(11)	(24)
Other operating		5,665	4,759
Other operating—intercompany		(757)	(683)
Total operating expenses		10,205	8,691
Equity in undistributed income of subsidiaries		0	0
Income (loss) from continuing operations before income taxes		5,120	9,242
Provision (benefits) for income taxes		1,459	2,097
Income (loss) from continuing operations		3,661	7,145
Income (loss) from discontinued operations, net of taxes		(2)	(2)
Net income (loss) before attribution of noncontrolling interests		3,659	7,143
Noncontrolling interests		17	33
Citigroup’s net income		3,642	7,110
Comprehensive income
Add: Other comprehensive income (loss)		(2,070)	537
Total Citigroup comprehensive income (loss)		1,572	7,647
Add: Other comprehensive income (loss) attributable to noncontrolling interests		(29)	(58)
Add: Net income (loss) attributable to noncontrolling interests		17	33
Total comprehensive income (loss)		1,560	7,622
Consolidating adjustments
Revenues
Dividends from subsidiaries		(250)	(100)
Interest revenue		0	0
Interest revenue—intercompany		0	0
Interest expense		0	0
Interest expense—intercompany		0	0
Net interest income		0	0
Commissions and fees		0	0
Commissions and fees—intercompany		0	0
Principal transactions		0	0
Principal transactions—intercompany		0	0
Other revenue		0	0
Other revenue—intercompany		0	0
Total non-interest revenues		0	0
Total revenues, net of interest expense		(250)	(100)
Total provisions for credit losses and for benefits and claims		0	0
Operating expenses
Compensation and benefits		0	0
Compensation and benefits—intercompany		0	0
Other operating		0	0
Other operating—intercompany		0	0
Total operating expenses		0	0
Equity in undistributed income of subsidiaries		(4,134)	(8,173)
Income (loss) from continuing operations before income taxes		(4,384)	(8,273)
Provision (benefits) for income taxes		0	0
Income (loss) from continuing operations		(4,384)	(8,273)
Income (loss) from discontinued operations, net of taxes		0	0
Net income (loss) before attribution of noncontrolling interests		(4,384)	(8,273)
Noncontrolling interests		0	0
Citigroup’s net income		(4,384)	(8,273)
Comprehensive income
Add: Other comprehensive income (loss)		1,621	(487)
Total Citigroup comprehensive income (loss)		(2,763)	(8,760)
Add: Other comprehensive income (loss) attributable to noncontrolling interests		0	0
Add: Net income (loss) attributable to noncontrolling interests		0	0
Total comprehensive income (loss)		$ (2,763)	$ (8,760)

[1] This total excludes the provision for credit losses on AFS securities, which is disclosed separately above.

[2] See Note 17.