Pension And Other Postretirement Employee Benefits (OPEB) Plans (Narrative) (Details) - 6 months ended Jun. 30, 2015 - USD ($) $ in Millions	Total
Oncor Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.95%
Expected return on plan assets	5.25%
EFH Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.19%
Expected return on plan assets	5.38%
Defined Benefit Pension Plans For 2015 To 2019 [Member]
Defined Benefit Plan Disclosure [Line Items]
Additional cash contributions	$ 373
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash contributions	2
Additional cash contributions	$ 49
OPEB Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.23%
Expected return on plan assets	6.65%
Cash contributions	$ 13
Additional cash contributions	12
OPEB Plan For 2015 To 2019 [Member]
Defined Benefit Plan Disclosure [Line Items]
Additional cash contributions	$ 147