Employee Benefit Plans Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	May. 31, 2015
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated employer contributions for 2015	$ 4
Contributions by employer	3
Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated employer contributions for 2015	1
Contributions by employer	$ 1
Defined Benefit Plan, Amount To Be Transferred		$ 150
Defined Benefit Plan, Net Periodic Benefit Cost Not Yet Recognized, Regulatory Deferrals, Before Tax		$ 9