CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Citigroup’s net income		$ 4,133	$ 3,840	$ 12,095	$ 11,339
Add: Citigroup's other comprehensive income
Net change in unrealized gains and losses on investment securities, net of taxes	[1]	(66)	(432)	127	2,529
Net change in debt valuation adjustment (DVA), net of taxes	[1]	(123)	(200)	(267)	5
Net change in cash flow hedges, net of taxes		8	(83)	123	385
Benefit plans liability adjustment, net of taxes		(29)	12	(176)	(480)
Net change in foreign currency translation adjustment, net of taxes and hedges		218	(375)	2,179	(273)
Citigroup’s total other comprehensive income		8	(1,078)	1,986	2,166
Citigroup’s total comprehensive income		4,141	2,762	14,081	13,505
Add: Other comprehensive income attributable to noncontrolling interests		12	10	82	(13)
Add: Net income attributable to noncontrolling interests		(1)	17	41	48
Total comprehensive income		$ 4,152	$ 2,789	$ 14,204	$ 13,540

[1] See Note 1 to the Consolidated Financial Statements.