Segments of Operations (Details 1) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Operating earnings before income taxes by significant business segment and sub-segment
Realized gains (losses)	$ 19	$ 11	$ 16	$ 15
Operating earnings before income taxes	69	158	164	305
Specialty Property and Transportation [Member]
Operating earnings before income taxes by significant business segment and sub-segment
Property and casualty insurance underwriting income (loss)		8	33	40
Specialty Casualty [Member]
Operating earnings before income taxes by significant business segment and sub-segment
Property and casualty insurance underwriting income (loss)	21	23	23	41
Specialty Financial [Member]
Operating earnings before income taxes by significant business segment and sub-segment
Property and casualty insurance underwriting income (loss)	13	33	23	54
Specialty Other [Member]
Operating earnings before income taxes by significant business segment and sub-segment
Property and casualty insurance underwriting income (loss)	5	4	6	10
Other Lines [Member]
Operating earnings before income taxes by significant business segment and sub-segment
Property and casualty insurance underwriting income (loss)	(50)	(5)	(50)	(11)
Property and Casualty Insurance [Member]
Operating earnings before income taxes by significant business segment and sub-segment
Property and casualty insurance underwriting income (loss)	(11)	63	35	134
Investment and other income, net	70	81	138	162
Realized gains (losses)	32	13	32	23
Operating earnings before income taxes	91	157	205	319
Annuity and Supplemental Insurance [Member]
Operating earnings before income taxes by significant business segment and sub-segment
Operations	56	46	108	90
Realized gains (losses)	(13)	(2)	(16)	(8)
Operating earnings before income taxes	43	44	92	82
Other Segment [Member]
Operating earnings before income taxes by significant business segment and sub-segment
Operating earnings before income taxes	$ (65)	$ (43)	$ (133)	$ (96)