Employee Benefit Plans Level 4 Net Periodic Benefits Cost and Other Recognized in the OCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Actuarial Gain (Loss), before Tax	$ 60	$ 45
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Service Cost	2	2	$ 1
Defined Benefit Plan, Interest Cost	235	258	238
Defined Benefit Plan, Expected Return on Plan Assets	(311)	(325)	(315)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0
Defined Benefit Plan, Amortization of Gains (Losses)	60	45	59
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements		128	0
Defined Benefit Plan, Net Periodic Benefit Cost	(14)	108	(17)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Other Comprehensive Income (Loss), Finalization of Pension and Other Postretirement Benefit Plan Valuation, before Tax	0	128
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax	0	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax	(185)	(622)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	(125)	(449)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	2,553	2,428
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax	0	0
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax	(2,553)	(2,428)
Defined Benefit Plan, Future Amortization of Gain (Loss)	55
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Actuarial Gain (Loss), before Tax	5	5
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Service Cost	0	0	0
Defined Benefit Plan, Interest Cost	12	14	11
Defined Benefit Plan, Expected Return on Plan Assets	(12)	(14)	(14)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(7)	(7)	(7)
Defined Benefit Plan, Amortization of Gains (Losses)	5	5	2
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	(2)	(2)	$ (8)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Other Comprehensive Income (Loss), Finalization of Pension and Other Postretirement Benefit Plan Valuation, before Tax	0	0
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax	(7)	(7)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax	(3)	(51)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	(5)	(53)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	123	124
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax	91	97
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax	(32)	$ (27)
Defined Benefit Plan, Future Amortization of Gain (Loss)	$ 5