Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Assets [Abstract]
Short Term Investments	$ 2,012	$ 1,893
Fixed Maturities (cost $34,975 and $34,762)	37,513	37,184
Equity Securities (cost $1,261 and $1,264)	1,583	1,512
Other Invested Assets	2,059	2,180
TOTAL INVESTED ASSETS	43,167	42,769
Cash	61	58
Accrued Investment Income	440	440
Premiums Receivable	2,279	2,161
Reinsurance Recoverable on Unpaid Losses and Loss Expenses	1,669	1,739
Prepaid Reinsurance Premiums	337	320
Deferred Policy Acquisition Costs	1,227	1,210	[1]
Goodwill	467	467
Other Assets	1,363	1,281
TOTAL ASSETS	51,010	50,445	[1]
Liabilities [Abstract]
Unpaid Losses and Loss Expenses	23,199	23,068
Unearned Premiums	6,433	6,322
Long Term Debt	3,575	3,575
Dividend Payable to Shareholders	110	107
Deferred Income Tax	96	2	[1]
Accrued Expenses and Other Liabilities	2,036	2,070
TOTAL LIABILITIES	35,449	35,144	[1]
Contingent Liabilities (Note 6)
Shareholders' Equity [Abstract]
Common Stock - $1 Par Value; 371,980,460 Shares	372	372
Paid-In Surplus	143	190
Retained Earnings	19,591	18,903	[1]
Accumulated Other Comprehensive Income	1,309	1,195
Treasury Stock, at Cost - 106,131,522 and 99,519,509 Shares	(5,854)	(5,359)
TOTAL SHAREHOLDERS' EQUITY	15,561	15,301	[1]
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 51,010	$ 50,445	[1]

[1] As Adjusted