Employee Benefit Plans Level 4 Obligations and Funded Status (Details) - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	$ 0
Trusts [Abstract]
Assets held in rabbi trusts and designated for non qualified pension plans.	127	$ 129
Fair value of pension plan assets under rabbi trust	0	0
Funded status of pension benefits including fair value of pension plan assets under rabbi trust	$ 1,177	0
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]
Expired, number of options	(53)
Projected benefit obligation	$ 5,734	6,025
Accumulated benefit obligation	5,732	6,024
Fair value of plan assets	4,430	4,707
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation	301	338	$ 312
Defined Benefit Plan, Service Cost	0	0	0
Defined Benefit Plan, Interest Cost	12	14	11
Defined Benefit Plan, Contributions by Plan Participants	25	26
Defined Benefit Plan, Actuarial Gain (Loss)	0	(38)
Defined Benefit Plan, Settlements, Benefit Obligation	0	0
Defined Benefit Plan, Plan Amendments	8	16
Defined Benefit Plan Benefit Obligation Benefits Paid	68	70
Defined Benefit Plan, Gross Prescription Drug Subsidy Receipts Received	2	2
Defined Benefit Plan, Foreign Currency Exchange Rate Gain (Loss)	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Funded Status of Plan	(139)	(142)
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	0	0
Defined Benefit Plan, Settlements, Plan Assets	0	0
Defined Benefit Plan Expenses Paid	0	0
Defined Benefit Plan, Benefits Paid	(36)	(33)
Defined Benefit Plan, Contributions by Employer	0	0
Defined Benefit Plan, Actual Return on Plan Assets	2	16
Defined Benefit Plan, Fair Value of Plan Assets	162	196	213
Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract]
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities	139	142
Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation	5,734	6,025	5,516
Defined Benefit Plan, Service Cost	2	2	1
Defined Benefit Plan, Interest Cost	235	258	238
Defined Benefit Plan, Contributions by Plan Participants	0	0
Defined Benefit Plan, Actuarial Gain (Loss)	(18)	8
Defined Benefit Plan, Settlements, Benefit Obligation	0	319
Defined Benefit Plan, Plan Amendments	236	846
Defined Benefit Plan Benefit Obligation Benefits Paid	307	268
Defined Benefit Plan, Gross Prescription Drug Subsidy Receipts Received	0	0
Defined Benefit Plan, Foreign Currency Exchange Rate Gain (Loss)	$ (3)	(2)
Mortality, Morbidity and Surrender Rate Assumption	279
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Support, Methodology and Source Data	567
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Funded Status of Plan	$ (1,304)	(1,318)
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	(3)	(1)
Defined Benefit Plan, Settlements, Plan Assets	0	319
Defined Benefit Plan Expenses Paid	(21)	(24)
Defined Benefit Plan, Benefits Paid	(282)	(245)
Defined Benefit Plan, Contributions by Employer	101	101
Defined Benefit Plan, Actual Return on Plan Assets	(72)	565
Defined Benefit Plan, Fair Value of Plan Assets	4,430	4,707	$ 4,630
Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract]
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent	$ 1,304	1,318
Lump Sum Benefit Payment [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Settlements, Benefit Obligation		274
Cash [Member] | Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Settlements, Benefit Obligation		$ 45