CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Citigroup’s net income		$ 4,710	$ 4,620
Add: Citigroup's other comprehensive income
Net change in unrealized gains and losses on debt securities, net of taxes	[1]	1,135	(1,058)
Net change in debt valuation adjustment (DVA), net of taxes	[1]	(571)	128
Net change in cash flow hedges, net of taxes		286	(222)
Benefit plans liability adjustment, net of taxes		(64)	88
Net change in foreign currency translation adjustment, net of taxes and hedges		58	1,120
Net change in excluded component of fair value hedges, net of taxes		18	(4)
Citigroup’s total other comprehensive income		862	52
Citigroup’s total comprehensive income		5,572	4,672
Add: Other comprehensive income (loss) attributable to noncontrolling interests		(13)	14
Add: Net income attributable to noncontrolling interests		25	22
Total comprehensive income		$ 5,584	$ 4,708

[1] See Note 1 to the Consolidated Financial Statements in Citi’s 2018 Annual Report on Form 10-K.