Segments of Operations (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes	$ 118		$ 102
Realized gains on securities	57		44
Earnings before income taxes	175		146
Property and Casualty Insurance [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	43		48
Investment and other income, net	56		55
Earnings before realized gains (losses) and income taxes	99		103
Annuity [Member]
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes	76		60
Run-off Long-term Care and Life [Member]
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes	(1)		1
Medicare Supplement and Critical Illness [Member]
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes		[1]	6	[1]
Other [Member]
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes	(56)	[2]	(68)	[2]
Specialty Property and transportation [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	10		27
Specialty casualty [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	19		4
Specialty financial [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	13		16
Specialty Other [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	6		1
Other Lines [Member]
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	$ (5)

[1] Sold in August 2012.

[2] Includes holding company expenses and $11 million and $28 million in losses of managed investment entities attributable to noncontrolling interests for the first quarter of 2013 and 2012, respectively.