Risk Management and Fair Values (Schedules Of Valuation Techniques) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014
Effect of Significant Unobservable Inputs on Fair Value of Electricity Swaps	$ (3)
Parent Company [Member]
Range From Average Percentage for Electricity Options	53.00%
Range from Average Percentage for Fair Value of Electricity Swaps	3.00%
Effect of Significant Unobservable Inputs on Fair Value of Electricity Options	35
Fair Value of Electricity Options	10
Fair Value of Electricity Swaps	$ (96)