CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Citigroup’s net income		$ 4,620	$ 4,090
Add: Citigroup's other comprehensive income
Net change in unrealized gains and losses on investment securities, net of taxes	[1],[2]	(1,058)	220
Net change in debt valuation adjustment (DVA), net of taxes	[2]	128	(60)
Net change in cash flow hedges, net of taxes		(222)	(2)
Benefit plans liability adjustment, net of taxes		88	(12)
Net change in foreign currency translation adjustment, net of taxes and hedges		1,120	1,318
Net change in excluded component of fair value hedges, net of taxes		(4)	0
Citigroup’s total other comprehensive income		52	1,464
Citigroup’s total comprehensive income		4,672	5,554
Add: Other comprehensive income attributable to noncontrolling interests		14	31
Add: Net income attributable to noncontrolling interests		22	10
Total comprehensive income		$ 4,708	$ 5,595

[1] For the three months ended March 31, 2018, amount represents the net change in unrealized gains and losses on available-for-sale (AFS) debt securities. Effective January 1, 2018, the AFS category is eliminated for equity securities under ASU 2016-01.

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