Pension Plan And Other Postretirement Benefits (Net Periodic Pension And Other Postretirement Benefit Costs) (Details) - Pension Benefits [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 3	$ 12	$ 10
Interest cost	1	1	4	4
Expected return on plan assets	$ (2)	$ (1)	$ (6)	$ (5)
Amortization of prior service cost
Amortization of net loss	$ 1		$ 2
Net periodic benefit cost	$ 4	$ 3	$ 12	$ 9