CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income before attribution of noncontrolling interests	$ 2,898		$ 3,278		$ 7,117		$ 11,394
Citigroup’s other comprehensive income (loss)
Net change in unrealized gains and losses on investment securities, net of taxes	(207)		(8)		1,227		(1,906)
Net change in cash flow hedges, net of taxes	28		330		266		952
Benefit plans liability adjustment, net of taxes	71	[1]	298	[1]	(106)	[1]	953	[1]
Net change in foreign currency translation adjustment, net of taxes and hedges	(1,721)		506		(2,230)		(1,901)
Citigroup’s total other comprehensive income (loss)	(1,829)		1,126		(843)		(1,902)
Other comprehensive income (loss) attributable to noncontrolling interests
Net change in unrealized gains and losses on investment securities, net of taxes	3		(3)		9		(29)
Net change in foreign currency translation adjustment, net of taxes	(58)		34		(66)		(15)
Total other comprehensive income (loss) attributable to noncontrolling interests	(55)		31		(57)		(44)
Total comprehensive income before attribution of noncontrolling interests	1,014		4,435		6,217		9,448
Total net income (loss) attributable to noncontrolling interests	59		51		154		177
Citigroup’s comprehensive income	$ 955		$ 4,384		$ 6,063		$ 9,271

[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.