Employee Benefit Plans Employee Benefit Plans - Contributions and Benefit Payments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	$ 10
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	102
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	108
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	109
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	104
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	104
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	470
Other Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	4
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	38
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	39
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	39
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	40
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	42
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	210
Prescription Drug Subsidy Receipts, Next Twelve Months	0
Prescription Drug Subsidy Receipts, Year Two	0
Prescription Drug Subsidy Receipts, Year Three	0
Prescription Drug Subsidy Receipts, Year Four	0
Prescription Drug Subsidy Receipts, Year Five	0
Prescription Drug Subsidy Receipts, after Year Five	$ (3)