Segments of Operations (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Segment Reporting Information [Line Items]
Total premiums earned									$ 3,204		$ 2,847		$ 2,759
Net investment income									1,346		1,301		1,225
Other income									97		89		84
Revenues before realized gains (losses)									4,875		4,586		4,570
Realized gains on securities									221		210		76
Realized gains (losses) on subsidiaries									(4)		161		(3)
Total revenues	1,362	1,443	1,139	1,148	1,208	1,538	1,124	1,087	5,092		4,957		4,643
Property and Casualty Insurance [Member]
Segment Reporting Information [Line Items]
Net investment income									263		275		291
Other income									15		24		26
Revenues before realized gains (losses)									3,482		3,146		3,076
Annuity [Member]
Segment Reporting Information [Line Items]
Net investment income									1,034		976		859
Other income									67		52		43
Revenues before realized gains (losses)									1,101		1,028		902
Run-off Long-term Care and Life [Member]
Segment Reporting Information [Line Items]
Revenues before realized gains (losses)									194		191		190
Medicare Supplement and Critical Illness [Member]
Segment Reporting Information [Line Items]
Revenues before realized gains (losses)									0	[1]	212	[1]	325	[1]
Other [Member]
Segment Reporting Information [Line Items]
Revenues before realized gains (losses)									98		9		77
Specialty Property and transportation [Member]
Segment Reporting Information [Line Items]
Total premiums earned									1,521		1,423		1,412
Specialty casualty [Member]
Segment Reporting Information [Line Items]
Total premiums earned									1,135		948		872
Specialty financial [Member]
Segment Reporting Information [Line Items]
Total premiums earned									469		405		408
Specialty Other [Member]
Segment Reporting Information [Line Items]
Total premiums earned									$ 79		$ 71		$ 67

[1] Sold in August 2012.