RETIREMENT BENEFITS (Details 9) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Early Retiree Reinsurance Program
Reimbursements received under Early Retiree Reinsurance Program		$ 8,000,000
Reimbursements used to reduce health benefit costs	3,000,000	5,000,000
Defined Contribution Plans
Maximum percentage contribution by employer of employees eligible pay	6.00%	6.00%
Maximum compensation to be eligible for fixed contribution from employer	100,000
Percentage of fixed contribution by employer, for eligible employees whose compensation is $100,000 or less	2.00%
Pretax expense associated with Citigroup 401(k) plan	394,000,000	384,000,000	374,000,000
Postemployment Plans
Postemployment Plans
Funded status recognized	(252,000,000)	(501,000,000)
Amount in accumulated other comprehensive income (loss)	46,000,000	(185,000,000)
Service cost	20,000,000	22,000,000	16,000,000
Interest cost	10,000,000	13,000,000	12,000,000
Prior service cost (benefit)	(3,000,000)	7,000,000	7,000,000
Net actuarial loss	17,000,000	13,000,000	9,000,000
Total service related expense	44,000,000	55,000,000	44,000,000
Non-service related expense (benefit)	(14,000,000)	24,000,000	23,000,000
Total net (benefit) expense	$ 30,000,000	$ 79,000,000	$ 67,000,000