SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Supplementary insurance information
Deferred policy acquisition costs	$ 504	$ 487	$ 467
Reserves for losses, loss expenses, life policy deposit contracts	5,306	5,170	5,187
Unearned premiums	2,365	2,178	2,082
Premiums earned	4,493	4,214	3,987
Net investment income	438	433	433
Benefits, claims, losses, and settlement expenses	3,480	3,444	2,900
Amortization of deferred policy acquisition costs	715	680	651
Other operating expenses	418	342	318
Net premiums written (excluding life)	4,603	4,255	4,019
Property and casualty insurance operations
Supplementary insurance information
Deferred policy acquisition costs	364	343	327
Reserves for losses, loss expenses, life policy deposit contracts	3,598	3,499	3,584
Unearned premiums	2,365	2,178	2,082
Premiums earned	4,422	4,149	3,925
Net investment income	327	324	325
Benefits, claims, losses, and settlement expenses	3,379	3,344	2,810
Amortization of deferred policy acquisition costs	705	668	635
Other operating expenses	397	327	303
Net premiums written (excluding life)	4,603	4,255	4,019
Life insurance operations
Supplementary insurance information
Deferred policy acquisition costs	140	144	140
Reserves for losses, loss expenses, life policy deposit contracts	1,708	1,671	1,603
Unearned premiums
Premiums earned	71	65	62
Net investment income	95	93	96
Benefits, claims, losses, and settlement expenses	101	100	90
Amortization of deferred policy acquisition costs	10	12	16
Other operating expenses	21	15	15
Net premiums written (excluding life)
Management operations
Supplementary insurance information
Deferred policy acquisition costs
Reserves for losses, loss expenses, life policy deposit contracts
Unearned premiums
Premiums earned
Net investment income	16	16	12
Benefits, claims, losses, and settlement expenses
Amortization of deferred policy acquisition costs
Other operating expenses
Net premiums written (excluding life)