Employee Benefit Plans Level 4 Obligations and Funded Status (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Contributions by Employer	$ 100
Trusts [Abstract]
Assets held in rabbi trusts and designated for non qualified pension plans.	129	123
Fair value of pension plan assets under rabbi trust	4,836	4,753
Funded status of pension benefits including fair value of pension plan assets under rabbi trust	1,189	763
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]
Expired, number of options	(503)
Projected benefit obligation	6,025	5,516
Accumulated benefit obligation	6,024	5,515
Fair value of plan assets	4,707	4,630
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation	338	312	313
Defined Benefit Plan, Service Cost	0	0	2
Defined Benefit Plan, Interest Cost	14	11	14
Defined Benefit Plan, Contributions by Plan Participants	26	24
Defined Benefit Plan, Actuarial Gain (Loss)	(38)	(39)
Defined Benefit Plan, Settlements, Benefit Obligation	0	0
Defined Benefit Plan, Plan Amendments	(16)	(19)
Defined Benefit Plan Benefit Obligation Benefits Paid	70	58
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	(142)	(99)
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	(33)	(20)
Defined Benefit Plan, Contributions by Employer	0	0
Defined Benefit Plan, Actual Return on Plan Assets	16	13
Defined Benefit Plan, Fair Value of Plan Assets	196	213	220
Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract]
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities	142	99
Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation	6,025	5,516	6,080
Defined Benefit Plan, Service Cost	2	1	92
Defined Benefit Plan, Interest Cost	258	238	250
Defined Benefit Plan, Contributions by Plan Participants	0	0
Defined Benefit Plan, Actuarial Gain (Loss)	8	(14)
Defined Benefit Plan, Settlements, Benefit Obligation	319	0
Defined Benefit Plan, Plan Amendments	(846)	(508)
Defined Benefit Plan Benefit Obligation Benefits Paid	268	308
Defined Benefit Plan, Gross Prescription Drug Subsidy Receipts Received	0	0
Defined Benefit Plan, Foreign Currency Exchange Rate Gain (Loss)	(2)	(1)
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	(1,318)	(886)
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	(1)	(1)
Defined Benefit Plan, Settlements, Plan Assets	319	0
Defined Benefit Plan Expenses Paid	(24)	(15)
Defined Benefit Plan, Benefits Paid	(245)	(278)
Defined Benefit Plan, Contributions by Employer	101	101
Defined Benefit Plan, Actual Return on Plan Assets	565	(27)
Defined Benefit Plan, Fair Value of Plan Assets	4,707	4,630	4,850
Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract]
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent	1,318	886
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]
Accumulated benefit obligation	6,024	5,515
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