Schedule II - Condensed Financial Information, Statements of Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating expenses:
Loss on extinguishment of debt			$ 0	$ 100
Total operating expenses	$ 2,428	$ 2,171	7,038	6,587
Income before Income Taxes	742	878	2,374	2,668
Income tax expense (benefit)	290	334	905	1,009
Shareholders' Net Income	456	547	1,485	1,668
Shareholders' other comprehensive income (loss):
Net unrealized appreciation (depreciation) on securities	66	8	416	(138)
Net unrealized appreciation (depreciation), derivatives	(1)	3	(5)	15
Net translation of foreign currencies	55	(112)	96	(198)
Postretirement benefits liability adjustment	9	11	28	42
Shareholders' other comprehensive income (loss)	129	(90)	535	(279)
Shareholders' comprehensive income (loss)	$ 585	$ 457	$ 2,020	$ 1,389