CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - Condensed Consolidating Statements of Income and Comprehensive Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues
Dividends from subsidiaries		$ 0	$ 0	$ 0
Interest revenue		74,408	50,475	58,089
Interest revenue—intercompany		0	0	0
Interest expense		25,740	7,981	13,338
Interest expense—intercompany		0	0	0
Net interest income		48,668	42,494	44,751
Commissions and fees		9,175	13,672	11,385
Commissions and fees—intercompany		0	0	0
Principal transactions		14,159	10,154	13,885
Principal transactions—intercompany		0	0	0
Other revenue		3,336	5,564	5,480
Other revenue—intercompany		0	0	0
Total non-interest revenues		26,670	29,390	30,750
Total revenues, net of interest expense		75,338	71,884	75,501
Provisions for credit losses and for benefits and claims	[1]	5,239	(3,778)	17,495
Operating expenses
Compensation and benefits		26,655	25,134	22,214
Compensation and benefits—intercompany		0	0	0
Other operating		24,637	23,059	22,160
Other operating—intercompany		0	0	0
Total operating expenses		51,292	48,193	44,374
Equity in undistributed income of subsidiaries		0	0	0
Income from continuing operations before income taxes		18,807	27,469	13,632
Provision for income taxes		3,642	5,451	2,525
Income from continuing operations		15,165	22,018	11,107
Income (loss) from discontinued operations, net of taxes		(231)	7	(20)
Net income before attribution of noncontrolling interests		14,934	22,025	11,087
Noncontrolling interests		89	73	40
Citigroup’s net income		14,845	21,952	11,047
Comprehensive income
Add: Other comprehensive income (loss)		(8,297)	(6,707)	4,260
Citigroup’s total comprehensive income		6,548	15,245	15,307
Add: Other comprehensive income (loss) attributable to noncontrolling interests		(58)	(99)	26
Add: Net income attributable to noncontrolling interests		89	73	40
Total comprehensive income		6,579	15,219	15,373
Consolidating adjustments
Revenues
Dividends from subsidiaries		(8,992)	(6,482)	(2,355)
Interest revenue		0	0	0
Interest revenue—intercompany		0	0	0
Interest expense		0	0	0
Interest expense—intercompany		0	0	0
Net interest income		0	0	0
Commissions and fees		0	0	0
Commissions and fees—intercompany		0	0	0
Principal transactions		0	0	0
Principal transactions—intercompany		0	0	0
Other revenue		0	0	0
Other revenue—intercompany		0	0	0
Total non-interest revenues		0	0	0
Total revenues, net of interest expense		(8,992)	(6,482)	(2,355)
Provisions for credit losses and for benefits and claims		0	0	0
Operating expenses
Compensation and benefits		0	0	0
Compensation and benefits—intercompany		0	0	0
Other operating		0	0	0
Other operating—intercompany		0	0	0
Total operating expenses		0	0	0
Equity in undistributed income of subsidiaries		(6,173)	(16,596)	(9,894)
Income from continuing operations before income taxes		(15,165)	(23,078)	(12,249)
Provision for income taxes		0	0	0
Income from continuing operations		(15,165)	(23,078)	(12,249)
Income (loss) from discontinued operations, net of taxes		0	0	0
Net income before attribution of noncontrolling interests		(15,165)	(23,078)	(12,249)
Noncontrolling interests		0	0	0
Citigroup’s net income		(15,165)	(23,078)	(12,249)
Comprehensive income
Add: Other comprehensive income (loss)		4,174	526	(4,021)
Citigroup’s total comprehensive income		(10,991)	(22,552)	(16,270)
Add: Other comprehensive income (loss) attributable to noncontrolling interests		0	0	0
Add: Net income attributable to noncontrolling interests		0	0	0
Total comprehensive income		(10,991)	(22,552)	(16,270)
Citigroup parent company | Reportable legal entities
Revenues
Dividends from subsidiaries		8,992	6,482	2,355
Interest revenue		0	0	0
Interest revenue—intercompany		4,628	3,757	4,162
Interest expense		5,250	4,791	4,992
Interest expense—intercompany		715	294	502
Net interest income		(1,337)	(1,328)	(1,332)
Commissions and fees		0	0	0
Commissions and fees—intercompany		(1)	(36)	(36)
Principal transactions		5,147	976	(1,254)
Principal transactions—intercompany		(5,686)	(1,375)	693
Other revenue		210	(64)	(127)
Other revenue—intercompany		(220)	(133)	111
Total non-interest revenues		(550)	(632)	(613)
Total revenues, net of interest expense		7,105	4,522	410
Provisions for credit losses and for benefits and claims		0	0	0
Operating expenses
Compensation and benefits		9	10	(5)
Compensation and benefits—intercompany		12	69	191
Other operating		85	83	37
Other operating—intercompany		15	11	15
Total operating expenses		121	173	238
Equity in undistributed income of subsidiaries		6,173	16,596	9,894
Income from continuing operations before income taxes		13,157	20,945	10,066
Provision for income taxes		(1,688)	(1,007)	(981)
Income from continuing operations		14,845	21,952	11,047
Income (loss) from discontinued operations, net of taxes		0	0	0
Net income before attribution of noncontrolling interests		14,845	21,952	11,047
Noncontrolling interests		0	0	0
Citigroup’s net income		14,845	21,952	11,047
Comprehensive income
Add: Other comprehensive income (loss)		(8,297)	(6,707)	4,260
Citigroup’s total comprehensive income		6,548	15,245	15,307
Add: Other comprehensive income (loss) attributable to noncontrolling interests		0	0	0
Add: Net income attributable to noncontrolling interests		0	0	0
Total comprehensive income		6,548	15,245	15,307
CGMHI | Reportable legal entities
Revenues
Dividends from subsidiaries			0	0
Interest revenue		10,021	3,566	5,364
Interest revenue—intercompany		2,324	531	920
Interest expense		5,938	778	1,989
Interest expense—intercompany		4,358	1,320	2,170
Net interest income		2,049	1,999	2,125
Commissions and fees		4,617	7,770	6,216
Commissions and fees—intercompany		127	407	290
Principal transactions		13,895	10,140	(4,252)
Principal transactions—intercompany		(10,532)	(6,721)	9,064
Other revenue		493	576	706
Other revenue—intercompany		(58)	(60)	23
Total non-interest revenues		8,542	12,112	12,047
Total revenues, net of interest expense		10,591	14,111	14,172
Provisions for credit losses and for benefits and claims		10	6	(1)
Operating expenses
Compensation and benefits		5,450	5,251	4,941
Compensation and benefits—intercompany		0	0	0
Other operating		2,962	2,868	2,393
Other operating—intercompany		2,705	2,826	2,317
Total operating expenses		11,117	10,945	9,651
Equity in undistributed income of subsidiaries		0	0	0
Income from continuing operations before income taxes		(536)	3,160	4,522
Provision for income taxes		(290)	625	1,249
Income from continuing operations		(246)	2,535	3,273
Income (loss) from discontinued operations, net of taxes		0	0	0
Net income before attribution of noncontrolling interests		(246)	2,535	3,273
Noncontrolling interests		0	0	0
Citigroup’s net income		(246)	2,535	3,273
Comprehensive income
Add: Other comprehensive income (loss)		946	(76)	(223)
Citigroup’s total comprehensive income		700	2,459	3,050
Add: Other comprehensive income (loss) attributable to noncontrolling interests		0	0	0
Add: Net income attributable to noncontrolling interests		0	0	0
Total comprehensive income		700	2,459	3,050
Other Citigroup subsidiaries and eliminations | Reportable legal entities
Revenues
Dividends from subsidiaries		0	0	0
Interest revenue		64,387	46,909	52,725
Interest revenue—intercompany		(6,952)	(4,288)	(5,082)
Interest expense		14,552	2,412	6,357
Interest expense—intercompany		(5,073)	(1,614)	(2,672)
Net interest income		47,956	41,823	43,958
Commissions and fees		4,558	5,902	5,169
Commissions and fees—intercompany		(126)	(371)	(254)
Principal transactions		(4,883)	(962)	19,391
Principal transactions—intercompany		16,218	8,096	(9,757)
Other revenue		2,633	5,052	4,901
Other revenue—intercompany		278	193	(134)
Total non-interest revenues		18,678	17,910	19,316
Total revenues, net of interest expense		66,634	59,733	63,274
Provisions for credit losses and for benefits and claims		5,229	(3,784)	17,496
Operating expenses
Compensation and benefits		21,196	19,873	17,278
Compensation and benefits—intercompany		(12)	(69)	(191)
Other operating		21,590	20,108	19,730
Other operating—intercompany		(2,720)	(2,837)	(2,332)
Total operating expenses		40,054	37,075	34,485
Equity in undistributed income of subsidiaries		0	0	0
Income from continuing operations before income taxes		21,351	26,442	11,293
Provision for income taxes		5,620	5,833	2,257
Income from continuing operations		15,731	20,609	9,036
Income (loss) from discontinued operations, net of taxes		(231)	7	(20)
Net income before attribution of noncontrolling interests		15,500	20,616	9,016
Noncontrolling interests		89	73	40
Citigroup’s net income		15,411	20,543	8,976
Comprehensive income
Add: Other comprehensive income (loss)		(5,120)	(450)	4,244
Citigroup’s total comprehensive income		10,291	20,093	13,220
Add: Other comprehensive income (loss) attributable to noncontrolling interests		(58)	(99)	26
Add: Net income attributable to noncontrolling interests		89	73	40
Total comprehensive income		$ 10,322	$ 20,067	$ 13,286

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