Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net Income	$ 494	$ 499	$ 869	$ 948
Other Comprehensive Income (Loss), Net of Tax
Change in Unrealized Appreciation of Investments	(375)	238	(266)	473
Change in Postretirement Benefit Costs Not Yet Recognized in Net Income	7	5	24	11
Foreign Currency Translation Gains (Losses)	15	4	(161)	(15)
Total Other Comprehensive Income (Loss) Net of Tax	(353)	247	(403)	469
Comprehensive Income	$ 141	$ 746	$ 466	$ 1,417