CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income before attribution of noncontrolling interests	$ 231		$ 4,218		$ 4,219		$ 8,116
Citigroup’s other comprehensive income (loss)
Net change in unrealized gains and losses on investment securities, net of taxes	1,006		(2,043)		1,434		(1,898)
Net change in cash flow hedges, net of taxes	120		497		238		622
Benefit plans liability adjustment, net of taxes	(144)	[1]	401	[1]	(177)	[1]	655	[1]
Net change in foreign currency translation adjustment, net of taxes and hedges	17		(1,720)		(509)		(2,407)
Citigroup’s total other comprehensive income (loss)	999		(2,865)		986		(3,028)
Other comprehensive income (loss) attributable to noncontrolling interests
Net change in unrealized gains and losses on investment securities, net of taxes	8		(10)		6		(26)
Net change in foreign currency translation adjustment, net of taxes	(2)		(14)		(8)		(49)
Total other comprehensive income (loss) attributable to noncontrolling interests	6		(24)		(2)		(75)
Total comprehensive income before attribution of noncontrolling interests	1,236		1,329		5,203		5,013
Total comprehensive income (loss) attributable to noncontrolling interests	50		12		95		51
Citigroup’s comprehensive income	$ 1,186		$ 1,317		$ 5,108		$ 4,962

[1] Primarily reflects adjustments based on the quarterly actuarial valuations of the Company’s significant pension and postretirement plans and amortization of amounts previously recognized in Other comprehensive income.