Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net income (loss)	$ 77	$ (708)	$ 712	$ (2,433)
Mandatory convertible preferred stock dividend	27	27	81	81
Participating securities - mandatory convertible preferred stock	7		83
Net Income (Loss) Attributable to Common Stock	$ 43	$ (735)	$ 548	$ (2,514)
Number of common shares: Weighted average outstanding	499,812,926	482,485,150	496,458,435	417,222,661
Number of common shares: Issued upon assumed exercise of outstanding stock options
Number of common shares: Effect of issuance of non-vested restricted common stock	1,202,585		883,512
Number of common shares: Effect of issuance of non-vested performance units	1,275,268		1,185,724
Number of common shares: Effect of issuance of mandatory convertible preferred stock
Number of common shares: Weighted average and potential dilutive outstanding	502,290,779	482,485,150	498,527,671	417,222,661
Earnings (loss) per common share: Basic	$ 0.09	$ (1.52)	$ 1.11	$ (6.02)
Earnings (loss) per common share: Diluted	$ 0.09	$ (1.52)	$ 1.10	$ (6.02)