Pension Plan And Other Postretirement Benefits (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost (gain)		$ 12	$ 4	$ 16	$ 8
Net gain incurred in period	[1]	$ 4		4
Employer contributions				6
Company's expected additional annual contribution				$ 5
Common Stock in Treasury, Shares		31,269		31,269		47,149
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-cash curtailment gain (loss)		$ (1)		$ (1)
Settlement loss		(8)		(8)
Benefit obligation		$ 40		$ 40		$ 31
Discount rate		4.20%		4.20%			4.60%
Pension Benefits [Member] | One-time Termination Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Lump-sum payment		$ 28
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-cash curtailment gain (loss)		6
Net periodic benefit cost (gain)		(6)	$ 1	$ (5)	$ 2
Benefit obligation		$ 12		$ 12		$ 20
Discount rate		4.20%		4.20%			4.60%
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Common stock purchased under the terms of the Non-Qualified Plan presented as treasury stock				31,269		47,149

[1] Net of $1 million in taxes for the three and six months ended June 30, 2016.