Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 421	$ 164	$ 375
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	44	42	41
Realized gains on investments, net	(42)	(70)	(159)
Stock-based compensation	16	13	11
Interest credited to contract holders	44	51	48
Deferred income tax (benefit) expense	26	(18)	29
Changes in:
Investment income receivable	4		(1)
Premiums and reinsurance receivable	(122)	(128)	80
Deferred policy acquisition costs	(28)	(30)	(20)
Other assets	(4)	2	3
Loss and loss expense reserves	(109)	139	58
Life policy reserves	72	76	113
Unearned premiums	159	80	44
Other liabilities	78	(49)	(18)
Current income tax receivable/payable	79	(25)	(73)
Net cash provided by operating activities	638	247	531
CASH FLOWS FROM INVESTING ACTIVITIES
Sale of fixed maturities	144	71	199
Call or maturity of fixed maturities	927	808	886
Sale of equity securities	216	539	273
Purchase of fixed maturities	(1,166)	(1,087)	(1,483)
Purchase of equity securities	(425)	(337)	(396)
Change in short-term investments, net			7
Investment in buildings and equipment, net	(6)	(7)	(17)
Investment in finance receivables	(33)	(32)	(27)
Collection of finance receivables	34	30	29
Change in other invested assets, net	5	7
Net cash provided by investing activities	(304)	(8)	(529)
CASH FLOWS FROM FINANCING ACTIVITIES
Payment of cash dividends to shareholders	(256)	(255)	(252)
Purchase of treasury shares		(32)	(10)
Increase in notes payable		55
Proceeds from stock options exercised	10	1	0
Contract holders' funds deposited	99	172	170
Contract holders' funds withdrawn	(126)	(121)	(74)
Excess tax benefits on share-based compensation	1	5	2
Other	(13)	(11)	(10)
Net cash used in financing activities	(285)	(186)	(174)
Net change in cash and cash equivalents	49	53	(172)
Cash and cash equivalents at beginning of year	438	385	557
Cash and cash equivalents at end of period	487	438	385
Supplemental disclosures of cash flow information:
Interest paid	54	53	53
Income taxes paid	38	51	167
Non-cash activities:
Conversion of investment securities	26		5
Equipment acquired under capital lease obligations	23	28
Cashless exercise of stock options	$ 12