Employee Benefit Plans, Net Periodic Benefit Costs Amortized from Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Pension Plans [Member]
Pension and Other Postretirement Benefit Plans Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year
Amortization of prior service credit	$ (22)
Amortization of net actuarial loss	63
Total	41
Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Benefit Plans Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year
Amortization of prior service credit	(18)
Amortization of net actuarial loss	0
Total	$ (18)