Income Taxes (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes on Continuing Operations (Table Amounts)
Current federal income tax expense (benefit)	$ 661	$ 310	$ 701
Deferred federal income tax expense (benefit)	49	472	155
Total federal income tax expense (benefit)	710	782	856
Current foreign income tax expense (benefit)	14	21	10
Deferred foreign income tax expense (benefit)	(1)	(3)	2
Total foreign income tax expense (benefit)	13	18	12
Total federal and foreign income tax expense	$ 723	$ 800	$ 868