CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash Flows from Operating Activities
Net Income	$ 1,776	$ 1,443
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Increase (Decrease) in Unpaid Losses and Loss Expenses, Net	(303)	237
Increase in Unearned Premiums, Net	160	51
Decrease in Premiums Receivable	40	82
Change in Income Tax Payable or Recoverable	26	(1)
Amortization of Premiums and Discounts on Fixed Maturities	138	121
Depreciation	42	39
Realized Investment Gains, Net	(335)	(103)
Other, Net	(223)	(29)
Net Cash Provided by Operating Activities	1,321	1,840
Cash Flows from Investing Activities
Proceeds from Fixed Maturities - Sales	1,781	1,838
Proceeds from Fixed Maturities - Maturities, Calls and Redemptions	3,525	2,985
Proceeds from Sales of Equity Securities	399	128
Purchases of Fixed Maturities	(6,464)	(5,505)
Purchases of Equity Securities	(98)	(88)
Investments in Other Invested Assets, Net	394	248
Decrease (Increase) in Short Term Investments, Net	629	(384)
Change in Receivable or Payable from Security Transactions Not Settled, Net	88	136
Purchases of Property and Equipment, Net	(38)	(31)
Net Cash Provided by (Used in) Investing Activities	216	(673)
Cash Flows from Financing Activities
Repayment of Long Term Debt	(275)
Decrease in Funds Held Under Deposit Contracts	(5)	(8)
Proceeds from Issuance of Common Stock Under Stock-Based Employee Compensation Plans	38	68
Repurchase of Shares	(962)	(903)
Dividends Paid to Shareholders	(337)	(329)
Net Cash Used in Financing Activities	(1,541)	(1,172)
Net Decrease in Cash	(4)	(5)
Cash at Beginning of Year	50	58
Cash at End of Period	$ 46	$ 53