Consolidated Statement of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Cash flows from operating activities
Net income	$ 896		$ 806
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized investment gains	(10)	[1]	(10)	[1]
Depreciation and amortization	219		216
Deferred federal income tax expense	131		119
Amortization of deferred acquisition costs	948		971
Equity in income from other investments	(74)		(114)
Change in premiums receivable	(155)		(151)
Change in reinsurance recoverables	390		495
Change in deferred acquisition costs	(954)		(984)
Change in claims and claim adjustment expense reserves	(751)		(504)
Change in unearned premium reserves	187		117
Other operating activities	(297)		(147)
Net cash provided by operating activities	530		814
Cash flows from investing activities
Proceeds from maturities of fixed maturities	2,123		1,615
Proceeds from sales of investments, fixed maturities	234		223
Proceeds from sales of investments, equity securities	36		15
Proceeds from sales of investments, other investments	174		203
Purchases of investments, fixed maturities	(2,339)		(2,604)
Purchases of investments, equity securities	(13)		(10)
Purchases of investments, real estate investments	(6)		(5)
Purchases of investments, other investments	(95)		(114)
Net sales of short-term securities	109		226
Securities transactions in course of settlement	180		248
Other investing activities	(100)		(92)
Net cash provided by (used in) investing activities	303		(295)
Cash flows from financing activities
Payment of debt	(500)
Dividends paid to shareholders	(175)		(161)
Issuance of common stock - employee share options	98		77
Treasury stock acquired - share repurchase authorization	(300)		(354)
Treasury stock acquired - net employee share-based compensation	(58)		(52)
Excess tax benefits from share-based payment arrangements	21		12
Net cash used in financing activities	(914)		(478)
Effect of exchange rate changes on cash	(6)		3
Net increase (decrease) in cash	(87)		44
Cash at beginning of year	330		214
Cash at end of period	243		258
Supplemental disclosure of cash flow information
Income taxes paid	27		20
Interest paid	$ 35		$ 35

[1] Total other-than-temporary impairment (OTTI) gains were $0 million for each of the three months ended March 31, 2013 and 2012. Of total OTTI, credit losses of $(5) million and $(4) million for the three months ended March 31, 2013 and 2012, respectively, were recognized in net realized investment gains. In addition, unrealized gains from other changes in total OTTI of $5 million and $4 million for the three months ended March 31, 2013 and 2012, respectively, were recognized in other comprehensive income as part of changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income.