Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Flows From Operating Activities
Net Income	$ 591	$ 634	$ 525
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	48	52	51
Realized investment gains, net	(124)	(70)	(133)
Share-based compensation	23	20	19
Interest credited to contract holders'	48	44	47
Deferred income tax expense	38	16	37
Changes in:
Investment income receivable	(5)	(6)	(2)
Premiums and reinsurance receivable	(113)	(48)	(60)
Deferred policy acquisition costs	(26)	(18)	(20)
Other assets	34	(39)	19
Loss and loss expense reserves	367	233	174
Life policy reserves	102	101	119
Unearned premiums	106	119	106
Other liabilities	49	44	(11)
Current income tax receivable/payable	(35)	(18)	2
Net cash provided by operating activities	1,103	1,064	873
Cash Flows From Investing Activities
Sale of fixed maturities	15	43	26
Call or maturity of fixed maturities	1,511	1,199	1,019
Sale of equity securities	465	342	335
Purchase of fixed maturities	(1,994)	(1,722)	(1,312)
Purchase of equity securities	(439)	(493)	(392)
Investment in finance receivables	(17)	(14)	(18)
Collection of finance receivables	30	30	31
Investment in buildings and equipment, net	(13)	(10)	(9)
Change in other invested assets, net	(14)	1	9
Net cash used in investing activities	(456)	(624)	(311)
Cash Flows From Financing Activities
Payment of cash dividends to shareholders	(306)	(366)	(278)
Shares acquired - share repurchase authorization	(39)	(53)	(21)
Payments of note payable	(15)	(14)	(55)
Proceeds from stock options exercised	21	24	22
Contract holders' funds deposited	95	83	86
Contract holders' funds withdrawn	(155)	(148)	(143)
Excess tax benefits on share-based compensation	5	4	2
Other	(20)	(17)	(17)
Net cash used in financing activities	(414)	(487)	(404)
Net change in cash and cash equivalents	233	(47)	158
Cash and cash equivalents at beginning of year	544	591	433
Cash and cash equivalents at end of year	777	544	591
Supplemental Disclosures of Cash Flow Information
Interest paid	52	52	53
Income taxes paid	213	245	154
Noncash Activities
Conversion of securities	4	3	7
Equipment acquired under capital lease obligations	20	20	12
Cashless exercise of stock options	13	16	19
Other assets and other liabilities	$ 53	$ 27	$ 0