Retirement Plans (Schedule Of Net Periodic Benefit Cost (Credit) For Pension And Postretirement Plans) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 2	$ 2
Expected return on plan assets	(3)	(3)
Amortization of net actuarial (gain) loss	1	2
Net periodic benefit cost (credit)	1	1
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	$ 1	$ 0