Computation of Earnings (Loss) Per Basic/Diluted Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Numerator:
Consolidated net income (loss)	$ 293	$ 456
Less: Distributed earnings to unvested share-based awards that participate in earnings	(5)	(5)
Less: Undistributed earnings allocated to unvested share-based awards that participate in earnings	(3)	(5)
Numerator for basic earnings per common share-income (loss) available to common shareholders	$ 285	$ 446
Denominator:
Denominator for basic earnings per common share - weighted-average common shares outstanding (in shares)	709	1,113
Effect of potential dilutive common shares under the treasury stock method:
Employee stock options and others (in shares)	11	7
Denominator for diluted earnings per common share - weighted-average common shares outstanding plus dilutive effect of employee stock options and others (in shares)	720	1,120
Basic earnings per common share (in dollars per share)	$ 0.40	$ 0.40
Diluted earnings per common share (in dollars per share)	$ 0.40	$ 0.40
Common stock weighted-average shares, unvested restricted stock rights (in shares)	17	26
Options
Antidilutive [Line Items]
Antidilutive securities excluded from computation of diluted earnings per share (in shares)	3	14
Restricted Stocks
Antidilutive [Line Items]
Antidilutive securities excluded from computation of diluted earnings per share (in shares)	3