Earnings Per Share (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income	$ 78	$ 194
Preferred stock dividends	25
Mandatory convertible preferred stock dividend	25
Net income attributable to shareholders	53	194
Participating securities - mandatory convertible preferred stock	7
Net Income Attributable to Common Stock	$ 46	$ 194
Number of common shares, Weighted average outstanding	375,444,030	351,222,538
Number of common shares: Issued upon assumed exerciese of outstanding stock options		348,798
Number of common shares: Effect of issuance of nonvested restricted common stock	133,634	349,608
Number of common shares: Effect of issuance of nonvested performance units	390	64,877
Number of common shares: Effect of issuance of mandatory convertible preferred stock	0	0
Diluted	375,578,054	351,985,821
Basic	$ 0.12	$ 0.55
Diluted	$ 0.12	$ 0.55
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares	3,704,089	1,179,914
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares	1,916,645	29,688
Mandatory Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares	58,333,252