INCOME TAXES (Details 5) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Operating loss and tax credit carryforwards
Total APB 23 subsidiary NOL carryforwards	$ 200,000,000	$ 200,000,000
Amount of recognized net deferred tax asset for which realization is more likely than not	52,799,000,000	55,322,000,000
Amount of taxable income necessary to fully realize U.S. federal, state and local DTAs	98,000,000,000
U.S. Federal and New York State and City NOL carryforward period	20 years
U.S. foreign tax credit carryforward period	10 years
Limit on utilization of foreign tax credit carryforwards (as a percent)	35.00%	35.00%
Domestic losses allowed to be reclassified as foreign source income	64,000,000,000
Limit on domestic losses to be reclassified as foreign source income (as a percent)	50.00%
Amount of FTC carry-forwards	19,600,000,000	22,000,000,000
Decrease in deferred tax assets	2,400,000,000
Decrease in deferred tax assets due to FTC carry-forwards	2,500,000,000
Foreign
Operating loss and tax credit carryforwards
Tax credit carryforward	19,600,000,000	22,000,000,000
Foreign tax credits related to companies filing U.S. federal tax separate from Citigroup's consolidated U.S. federal tax return expected to be utilized in consolidated return	700,000,000
Amount of recognized net deferred tax asset for which realization is more likely than not	3,500,000,000	3,300,000,000
U.S. Federal
Operating loss and tax credit carryforwards
Tax credit carryforward	2,500,000,000	2,600,000,000
Net Operating Loss (NOL) carryforward	4,000,000,000	2,400,000,000
Amount of recognized net deferred tax asset for which realization is more likely than not	45,000,000,000	47,500,000,000
Amount of FTC carry-forwards	19,600,000,000	22,000,000,000
New York state tax authority
Operating loss and tax credit carryforwards
Net Operating Loss (NOL) carryforward	9,600,000,000	9,600,000,000
New York city tax authority
Operating loss and tax credit carryforwards
Net Operating Loss (NOL) carryforward	6,100,000,000	5,600,000,000
2016 | Foreign
Operating loss and tax credit carryforwards
Tax credit carryforward		400,000,000
2017 | Foreign
Operating loss and tax credit carryforwards
Tax credit carryforward	4,700,000,000	6,600,000,000
2018 | Foreign
Operating loss and tax credit carryforwards
Tax credit carryforward	5,200,000,000	5,300,000,000
2019 | Foreign
Operating loss and tax credit carryforwards
Tax credit carryforward	1,200,000,000	1,300,000,000
2020 | Foreign
Operating loss and tax credit carryforwards
Tax credit carryforward	3,100,000,000	2,300,000,000
2021 | Foreign
Operating loss and tax credit carryforwards
Tax credit carryforward	1,400,000,000	1,900,000,000
2022 | Foreign
Operating loss and tax credit carryforwards
Tax credit carryforward	3,300,000,000	4,200,000,000
2027 | U.S. Federal
Operating loss and tax credit carryforwards
Tax credit carryforward		300,000,000
Net Operating Loss (NOL) carryforward	200,000,000	200,000,000
2027 | New York state tax authority
Operating loss and tax credit carryforwards
Net Operating Loss (NOL) carryforward	100,000,000	100,000,000
2027 | New York city tax authority
Operating loss and tax credit carryforwards
Net Operating Loss (NOL) carryforward	100,000,000	100,000,000
2028 | U.S. Federal
Operating loss and tax credit carryforwards
Tax credit carryforward	400,000,000	400,000,000
Net Operating Loss (NOL) carryforward	100,000,000	100,000,000
2028 | New York state tax authority
Operating loss and tax credit carryforwards
Net Operating Loss (NOL) carryforward	6,500,000,000	7,200,000,000
2028 | New York city tax authority
Operating loss and tax credit carryforwards
Net Operating Loss (NOL) carryforward	3,900,000,000	3,700,000,000
2029 | U.S. Federal
Operating loss and tax credit carryforwards
Tax credit carryforward	400,000,000	400,000,000
2029 | New York state tax authority
Operating loss and tax credit carryforwards
Net Operating Loss (NOL) carryforward	2,000,000,000	1,900,000,000
2029 | New York city tax authority
Operating loss and tax credit carryforwards
Net Operating Loss (NOL) carryforward	1,500,000,000	1,600,000,000
2030 | U.S. Federal
Operating loss and tax credit carryforwards
Tax credit carryforward	400,000,000	500,000,000
Net Operating Loss (NOL) carryforward	300,000,000	300,000,000
2030 | New York state tax authority
Operating loss and tax credit carryforwards
Net Operating Loss (NOL) carryforward	100,000,000	400,000,000
2031 | U.S. Federal
Operating loss and tax credit carryforwards
Tax credit carryforward	400,000,000	500,000,000
Net Operating Loss (NOL) carryforward	1,700,000,000	1,800,000,000
2032 | U.S. Federal
Operating loss and tax credit carryforwards
Tax credit carryforward	500,000,000	500,000,000
2032 | New York state tax authority
Operating loss and tax credit carryforwards
Net Operating Loss (NOL) carryforward	900,000,000
2032 | New York city tax authority
Operating loss and tax credit carryforwards
Net Operating Loss (NOL) carryforward	600,000,000	200,000,000
2033 | U.S. Federal
Operating loss and tax credit carryforwards
Tax credit carryforward	400,000,000
Net Operating Loss (NOL) carryforward	1,700,000,000
Various
Operating loss and tax credit carryforwards
Total APB 23 subsidiary NOL carryforwards	200,000,000	200,000,000
2023 | Foreign
Operating loss and tax credit carryforwards
Foreign tax credits related to companies filing U.S. federal tax separate from Citigroup's consolidated U.S. federal tax return expected to be utilized in consolidated return	$ 700,000,000