Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flows from Operating Activities
Net Income	$ 2,345	$ 1,545	$ 1,678
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Increase (Decrease) in Unpaid Losses and Loss Expenses, Net	(582)	691	361
Increase in Unearned Premiums, Net	158	32	114
Increase in Premiums Receivable	(99)	(24)	(63)
Change in Income Tax Payable or Recoverable	93	(53)	(102)
Amortization of Premiums and Discounts on Fixed Maturities	183	163	147
Depreciation	55	54	58
Realized Investment Gains, Net	(402)	(193)	(288)
Other, Net	(20)	84	(27)
NET CASH PROVIDED BY OPERATING ACTIVITIES	1,731	2,299	1,878
Cash Flows from Investing Activities
Proceeds from Fixed Maturities - Sales	2,449	2,271	1,730
Proceeds from Fixed Maturities - Maturities, Calls and Redemptions	4,909	4,290	3,540
Proceeds from Sales of Equity Securities	545	160	167
Purchases of Fixed Maturities	(8,275)	(7,247)	(5,014)
Purchases of Equity Securities	(113)	(112)	(95)
Investments in Other Invested Assets, Net	498	293	285
Decrease (Increase) in Short Term Investments, Net	383	(629)	11
Change in Receivable or Payable from Security Transactions not Settled, Net	(86)	45	8
Purchases of Property and Equipment, Net	(52)	(43)	(52)
Other, Net	(6)
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	252	(972)	580
Cash Flows from Financing Activities
Repayment of Long Term Debt	(275)		(400)
Increase (Decrease) in Funds Held under Deposit Contracts	(6)	(12)	7
Proceeds from Issuance of Common Stock Under Stock-Based Employee Compensation Plans	38	74	80
Repurchase of Shares	(1,288)	(959)	(1,707)
Dividends Paid to Shareholders	(450)	(438)	(450)
NET CASH USED IN FINANCING ACTIVITIES	(1,981)	(1,335)	(2,470)
Net Increase (Decrease) in Cash	2	(8)	(12)
Cash at Beginning of Year	50	58	70
CASH AT END OF YEAR	$ 52	$ 50	$ 58