Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Net income (loss)	$ 284	$ (593)	$ 635	$ (1,725)
Mandatory convertible preferred stock dividend	27	27	54	54
Participating securities - mandatory convertible preferred stock	33		76
Net Income (Loss) Attributable to Common Stock	$ 224	$ (620)	$ 505	$ (1,779)
Number of common shares: Weighted average outstanding	496,419,815	385,594,815	494,753,391	384,232,831
Number of common shares: Issued upon assumed exercise of outstanding stock options			3,317
Number of common shares: Effect of issuance of non-vested restricted common stock	761,311		707,576
Number of common shares: Effect of issuance of non-vested performance units	1,043,473		1,163,559
Number of common shares: Effect of issuance of mandatory convertible preferred stock
Number of common shares: Weighted average and potential dilutive outstanding	498,224,599	385,594,815	496,627,843	384,232,831
Earnings (loss) per common share: Basic	$ 0.45	$ (1.61)	$ 1.02	$ (4.63)
Earnings (loss) per common share: Diluted	$ 0.45	$ (1.61)	$ 1.02	$ (4.63)