Consolidated Statements of Shareholders' Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement Of Comprehensive Income
Shareholders' Net Income	$ 560	$ 456	$ 1,971	$ 1,485
Shareholders' other comprehensive income (loss), net of tax:
Net unrealized appreciation (depreciation) on securities	(22)	66	52	416
Net unrealized appreciation (depreciation) on derivatives	0	(1)	(3)	(5)
Net translation of foreign currencies	34	55	173	96
Postretirement benefits liability adjustment	10	9	36	28
Shareholders' other comprehensive income (loss), net of tax	22	129	258	535
Shareholders' comprehensive income (loss)	$ 582	$ 585	$ 2,229	$ 2,020