Quarterly Operating Results (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2011

Quarterly Financial Information Disclosure [Abstract]

Schedule of quarterly operating results

	1st		2nd		3rd		4th		Total
	Quarter		Quarter		Quarter		Quarter		Year
2011
Revenues	$	1,039	$	1,093	$	1,335	$	1,283	$	4,750
Net earnings, including noncontrolling interests		49		37		107		127		320
Net earnings attributable to shareholders		83		55		96		109		343
Earnings attributable to shareholders per common share:
Basic	$	.80	$	.53	$	.96	$	1.11	$	3.39
Diluted		.79		.52		.94		1.10		3.33
Average number of Common Shares:
Basic		104.6		102.7		99.7		98.2		101.3
Diluted		106.2		104.4		101.3		99.8		102.9
2010
Revenues	$	1,034	$	1,052	$	1,255	$	1,156	$	4,497
Net earnings, including noncontrolling interests		88		100		126		109		423
Net earnings attributable to shareholders		106		108		132		133		479
Earnings attributable to shareholders per common share:
Basic	$	.94	$	.98	$	1.22	$	1.24	$	4.38
Diluted		.93		.97		1.21		1.23		4.33
Average number of Common Shares:
Basic		112.0		110.2		108.2		106.7		109.2
Diluted		113.1		111.8		109.5		108.1		110.5

Quarterly information on realized gains (losses) on securities and favorable (unfavorable) development on unpaid loss and loss adjustment expenses

	1st		2nd			3rd		4th		Total
	Quarter		Quarter			Quarter		Quarter		Year
Realized Gains on Securities
2011	$	—	$	19		$	8	$	49	$	76
2010		4		11			57		29		101
Prior Year Development Favorable (Unfavorable)
2011	$	21	$	(13	)	$	34	$	27	$	69
2010		39		57			14		48		158