Segments of Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Total premiums earned	$ 931	$ 709	$ 1,685	$ 1,396
Net investment income	379	332	740	658
Other income	26	25	47	47
Revenues before realized gains (losses)	1,380	1,098	2,572	2,189
Realized gains on securities	12	41	31	98
Total revenues	1,392	1,139	2,603	2,287
Property and Casualty Insurance [Member]
Segment Reporting Information [Line Items]
Net investment income	76	65	143	131
Other income	2	6	4	9
Revenues before realized gains (losses)	1,009	780	1,832	1,536
Annuity [Member]
Segment Reporting Information [Line Items]
Net investment income	289	257	564	505
Other income	19	15	37	29
Revenues before realized gains (losses)	308	272	601	534
Run-off Long-term Care and Life [Member]
Segment Reporting Information [Line Items]
Revenues before realized gains (losses)	48	47	99	97
Other [Member]
Segment Reporting Information [Line Items]
Revenues before realized gains (losses)	15	(1)	40	22
Specialty Property and transportation [Member]
Segment Reporting Information [Line Items]
Total premiums earned	324	301	625	594
Specialty casualty [Member]
Segment Reporting Information [Line Items]
Total premiums earned	467	277	780	536
Specialty financial [Member]
Segment Reporting Information [Line Items]
Total premiums earned	116	113	233	229
Specialty Other [Member]
Segment Reporting Information [Line Items]
Total premiums earned	$ 24	$ 18	$ 47	$ 37