Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Consolidated Statements of Comprehensive Income
Net income	$ 533	$ 298	$ 1,443	$ 1,226
Other Comprehensive Income (Loss), Net of Tax
Change in Unrealized Appreciation of Investments	229	131	350	363
Change in Unrealized Other-Than-Temporary Impairment Losses on Investments		1	2	2
Foreign Currency Translation Gains (Losses)	20	(29)	(17)	56
Amortization of Net Actuarial Loss and Prior Service Cost Included in Net Postretirement Benefit Costs	12	12	40	34
Total Other Comprehensive Income, Net of Tax	261	115	375	455
Comprehensive Income	$ 794	$ 413	$ 1,818	$ 1,681