LIABILITY FOR UNPAID CLAIMS AND CLAIMS ADJUSTMENT EXPENSE, FUTURE POLICY BENEFITS FOR LIFE AND ACCIDENT AND HEALTH INSURANCE CONTRACTS, AND POLICYHOLDER CONTRACT DEPOSITS (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
LIABILITY FOR UNPAID CLAIMS AND CLAIMS ADJUSTMENT EXPENSE, FUTURE POLICY BENEFITS FOR LIFE AND ACCIDENT AND HEALTH INSURANCE CONTRACTS, AND POLICYHOLDER CONTRACT DEPOSITS
Gross loss reserves before reinsurance and discount, net of contractual deductible recoverable amounts due from policyholders	$ 12,000,000,000	$ 11,700,000,000
Collateral held for deductible recoverable amounts	9,000,000,000	8,300,000,000
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	87,991,000,000	91,145,000,000	91,151,000,000
Reinsurance recoverable, balance at the beginning of the year	(19,209,000,000)	(20,320,000,000)	(19,644,000,000)
Liability for unpaid claims and claims adjustment expense, Net of Reinsurance	68,782,000,000	70,825,000,000	71,507,000,000
Foreign exchange effect	(617,000,000)	(90,000,000)	353,000,000
Dispositions	(79,000,000)	(11,000,000)
Changes in net loss reserves due to retroactive asbestos reinsurance transaction	22,000,000	90,000,000	(1,703,000,000)
Total	68,108,000,000	70,814,000,000	70,157,000,000
Losses and loss expenses incurred
Current year	22,171,000,000	25,385,000,000	27,931,000,000
Prior years, other than accretion of discount	557,000,000	421,000,000	195,000,000
Prior years, accretion of discount	(309,000,000)	(63,000,000)	34,000,000
Total	22,419,000,000	25,743,000,000	28,160,000,000
Losses and loss expenses paid
Current year	7,431,000,000	8,450,000,000	11,534,000,000
Prior years	18,780,000,000	19,325,000,000	15,958,000,000
Total	26,211,000,000	27,775,000,000	27,492,000,000
Net liability for unpaid claims and claims adjustment expense, balance at the end of the year	64,316,000,000	68,782,000,000	70,825,000,000
Reinsurance recoverable, balance at the end of the year	17,231,000,000	19,209,000,000	20,320,000,000
Total, balance at the end of the year	81,547,000,000	87,991,000,000	91,145,000,000
Foreign exchange effect reclassified losses and loss expenses paid (current year)		847,000,000
Decrease in foreign exchange effect		847,000,000
Loss sensitive premium adjustment	89,000,000	54,000,000	172,000,000
Excess Casualty
Losses and loss expenses incurred
Total	144,000,000	157,000,000	(588,000,000)
Environmental and pollution
Losses and loss expenses incurred
Total	269,000,000	200,000,000	385,000,000
Primary casualty
Losses and loss expenses incurred
Total	498,000,000	531,000,000	686,000,000
Healthcare
Losses and loss expenses incurred
Total	$ 54,000,000	$ 68,000,000	$ 45,000,000