BUSINESS SEGMENTS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Segment reporting information
Revenues, net of interest expense	$ 19,604	[1],[2]	$ 17,904	[1],[2]	$ 59,070	[1],[2]	$ 58,640	[1],[2]
Provision for income taxes	1,985		1,080		5,873		4,777
Income (loss) from continuing operations	2,914	[3]	3,186	[3]	7,118	[3]	11,305	[3]
Pretax provisions (credits) for credit losses and for benefits and claims	1,750		1,959		5,454		6,442
Citicorp | North America
Segment reporting information
Revenues, net of interest expense	8,100		7,100		24,500		24,100
Citicorp | EMEA
Segment reporting information
Revenues, net of interest expense	2,600		2,500		8,500		9,100
Citicorp | Latin America
Segment reporting information
Revenues, net of interest expense	3,400		3,400		10,200		10,500
Citicorp | Asia
Segment reporting information
Revenues, net of interest expense	3,900		3,600		11,200		11,500
Global Consumer Banking
Segment reporting information
Regional business	4				4
Pretax provisions (credits) for credit losses and for benefits and claims	1,400		1,700		4,500		5,000
Institutional Clients Group
Segment reporting information
Number of countries where the entity provides a broad range of banking and financial products and services	100				100
Pretax provisions (credits) for credit losses and for benefits and claims	(21)		139		(106)		174
Citi Holdings
Segment reporting information
Pretax provisions (credits) for credit losses and for benefits and claims	400		100		1,000		1,300
Operating Segments | Total Citicorp and Corporate/Other
Segment reporting information
Revenues, net of interest expense	18,016	[2]	16,646	[2]	54,563	[2]	55,381	[2]
Provision for income taxes	1,887		1,218		5,821		5,813
Income (loss) from continuing operations	2,672	[3]	3,295	[3]	10,641	[3]	12,794	[3]
Operating Segments | Global Consumer Banking
Segment reporting information
Revenues, net of interest expense	9,637	[2]	9,232	[2]	28,311	[2]	28,696	[2]
Provision for income taxes	1,004		797		2,578		2,687
Income (loss) from continuing operations	1,937	[3]	1,535	[3]	5,269	[3]	5,222	[3]
Operating Segments | Institutional Clients Group
Segment reporting information
Revenues, net of interest expense	8,371	[2]	7,372	[2]	26,068	[2]	26,523	[2]
Provision for income taxes	1,019		605		3,389		3,430
Income (loss) from continuing operations	2,333	[3]	1,740	[3]	7,860	[3]	7,946	[3]
Operating Segments | Corporate/Other
Segment reporting information
Revenues, net of interest expense	8	[2]	42	[2]	184	[2]	162	[2]
Provision for income taxes	(136)		(184)		(146)		(304)
Income (loss) from continuing operations	(1,598)	[3]	20	[3]	(2,488)	[3]	(374)	[3]
Operating Segments | Citi Holdings
Segment reporting information
Revenues, net of interest expense	1,588	[2]	1,258	[2]	4,507	[2]	3,259	[2]
Provision for income taxes	98		(138)		52		(1,036)
Income (loss) from continuing operations	$ 242	[3]	$ (109)	[3]	$ (3,523)	[3]	$ (1,489)	[3]

[1] Certain prior period revenue and expense lines and totals were reclassified to conform to the current period’s presentation. See Note 3 to Notes to Consolidated Financial Statements.

[2] Includes Citicorp (excluding Corporate/Other) total revenues, net of interest expense, in North America of $8.1 billion and $7.1 billion; in EMEA of $2.6 billion and $2.5 billion; in Latin America of $3.4 billion and $3.4 billion; and in Asia of $3.9 billion and $3.6 billion for the three months ended September 30, 2014 and 2013, respectively. Includes Citicorp (excluding Corporate/Other) total revenues, net of interest expense, in North America of $24.5 billion and $24.1 billion; in EMEA of $8.5 billion and $9.1 billion; in Latin America of $10.2 billion and $10.5 billion; and in Asia of $11.2 billion and $11.5 billion for the nine months ended September 30, 2014 and 2013, respectively. Regional numbers exclude Citi Holdings and Corporate/Other, which largely operate within the U.S.

[3] Includes pretax provisions (credits) for credit losses and for benefits and claims in the GCB results of $1.4 billion and $1.7 billion; in the ICG results of $(21) million and $139 million; and in Citi Holdings results of $0.4 billion and $0.1 billion for the three months ended September 30, 2014 and 2013, respectively. Includes pretax provisions (credits) for credit losses and for benefits and claims in the GCB results of $4.5 billion and $5.0 billion; in the ICG results of $(106) million and $174 million; and in Citi Holdings results of $1.0 billion and $1.3 billion for the nine months ended September 30, 2014 and 2013, respectively.