LIABILITY FOR UNPAID CLAIMS AND CLAIMS ADJUSTMENT EXPENSE AND FUTURE POLICY BENEFITS FOR LIFE AND ACCIDENT AND HEALTH INSURANCE CONTRACTS AND POLICYHOLDER CONTRACT DEPOSITS (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Jun. 17, 2011
Reconciliation of activity in the Liability for unpaid claims and claims adjustment expense:
Liability for unpaid claims and claims adjustment expense, balance at the beginning of the year	$ 91,145	$ 91,151	$ 85,386
Reinsurance recoverable, balance at the beginning of the year	(20,320)	(19,644)	(17,487)	(1,700)
Total, balance at the beginning of the year	70,825	71,507	67,899
Foreign exchange effect	757	353	(126)
Acquisitions			1,538
Dispositions	(11)		(87)
Changes in net loss reserves due to NICO transaction	90	(1,703)
Total	71,661	70,157	69,224
Losses and loss expenses incurred
Current year	25,385	27,931	24,455
Prior years, other than accretion of discount	421	195	4,182
Prior years, accretion of discount	(63)	34	(562)
Total	25,743	28,160	28,075
Losses and loss expenses paid
Current year	9,297	11,534	9,873
Prior years	19,325	15,958	15,919
Total	28,622	27,492	25,792
Net liability for unpaid claims and claims adjustment expense, balance at the end of the year	68,782	70,825	71,507
Reinsurance recoverable, balance at the end of the year	19,209	20,320	19,644	1,700
Total, balance at the end of the year	87,991	91,145	91,151
Excess Casualty
Losses and loss expenses incurred
Total	262	(414)	1,100
Excess Workers' Compensation
Losses and loss expenses incurred
Total	46	145	793
Environmental
Losses and loss expenses incurred
Total	326	413
Asbestos
Losses and loss expenses incurred
Total			1,500
Loss sensitive premium adjustment
Losses and loss expenses paid
Net liability for unpaid claims and claims adjustment expense, balance at the end of the year	$ 54	$ 172	$ 8