Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Investments
Fixed maturities, at fair value (amortized cost: 2012-$8,222; 2011-$8,084)	$ 9,093	$ 8,779
Equity securities, at fair value (cost: 2012-$2,369; 2011-$2,162)	3,373	2,956
Other invested assets	68	66
Total investments	12,534	11,801
Cash and cash equivalents	487	438
Investment income receivable	115	119
Finance receivable	75	76
Premiums receivable	1,214	1,087
Reinsurance recoverable	615	622
Prepaid reinsurance premiums	26	24
Deferred policy acquisition costs	470	477
Land, building and equipment, net, for company use (accumulated depreciation: 2012-$397; 2011-$376)	217	227
Other assets	61	93
Separate accounts	734	671
Total assets	16,548	15,635
Insurance reserves
Loss and loss expense reserves	4,230	4,339
Life policy and investment contract reserves	2,295	2,214
Unearned premiums	1,792	1,633
Other liabilities	660	517
Deferred income tax	453	303
Note payable	104	104
Long-term debt and capital lease obligation	827	821
Separate accounts	734	671
Total liabilities	11,095	10,602
Commitments and contingent liabilities (Note 13)
SHAREHOLDERS' EQUITY
Common stock, par value-$2 per share; (authorized: 2012 and 2011-500 million shares, 2010-500 million shares; issued and outstanding: 2012-197 million shares, 2011-196 million shares	394	393
Paid-in capital	1,134	1,096
Retained earnings	4,021	3,863
Accumulated other comprehensive income	1,129	901
Treasury stock at cost	(1,225)	(1,220)
Total shareholders' equity	5,453	5,033
Total liabilities and shareholders' equity	$ 16,548	$ 15,635