Retirement Benefits and Trusteed Assets (OPEB - Target Allocations of Plan Assets) (Details) (Other Postretirement Benefit Plan [Member])	12 Months Ended
	Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	1
US Large Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.17
US Small Cap and Mid Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.04
Non US Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.2
Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.25
Hedge Funds and Similar Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.2
Private Equity and Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.14