Acquisitions And Divestitures (Summary Of Consolidated Results Of Operations On Pro Forma Basis) (Details) - Jun. 30, 2014 - Chesapeake Property Acquisition [Member] - USD ($) $ / shares in Units, $ in Millions	Total	Total
Business Acquisition [Line Items]
Revenues	$ 1,145	$ 2,396
Net Income	$ 242	$ 485
Basic	$ 0.47	$ 0.96
Diluted	$ 0.47	$ 0.96