Schedule II - Condensed Financial Information, Statements of Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Operating expenses:
Loss on extinguishment of debt		$ 100	$ 0	$ 100
Total operating expenses	$ 2,289	2,212	4,610	4,416
Income before Income Taxes	813	936	1,632	1,790
Income tax expense (benefit)	310	352	615	675
Shareholders' Net Income	510	588	1,029	1,121
Shareholders' other comprehensive income (loss):
Net unrealized appreciation (depreciation) on securities	177	(234)	350	(146)
Net unrealized appreciation (depreciation), derivatives	(1)	5	(4)	12
Net translation of foreign currencies	(40)	18	41	(86)
Postretirement benefits liability adjustment	8	20	19	31
Shareholders' other comprehensive income (loss)	144	(191)	406	(189)
Shareholders' comprehensive income (loss)	$ 654	$ 397	$ 1,435	$ 932