Employee Benefit Plans, Net Periodic Benefit Costs Amortized from Accumulated Other Comprehensive Income (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)
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	$ (20)
Amortization of net actuarial (gain) loss	49
Total	29
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	(16)
Amortization of net actuarial (gain) loss	(1)
Total	$ (17)