Consolidated Statements of Changes in Equity (Unaudited) (USD $) In Millions, except Share data	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Loss	Non-controlling Interest	Stockholders' Equity, Total [Member]
Beginning Balance at Dec. 31, 2012	$ 7,411	$ 3,587	$ 3,944	$ (158)	$ 38	$ 7,411
Beginning Balance, shares at Dec. 31, 2012	172,351,680	172,352,000
Net Income	342		339			342
Net Income (Loss) Attributable to Noncontrolling Interest	3				3
Dividends declared on common stock			(338)			(338)
Stock Issued During Period, Shares, New Issues		296,000
Issuance of common stock, value	3,762	19				19
Contribution of Common Stock to Pension Plan Shares	753,579	1,504,000
Contribution of Common Stock to Pension Plan	100	100				100
Foreign currency translation, net of tax	(2)			(2)		(2)
Benefit obligations, net of tax	5			5		5
Stock-based compensation, distributions to noncontrolling interests and other, shares		808,000
Stock-based compensation, distributions to noncontrolling interests and other		56				50
Stockholders' Equity, Other			0
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders					(6)
Ending Balance at Jun. 30, 2013	$ 7,587	$ 3,762	$ 3,945	$ (155)	$ 35	$ 7,587
Ending Balance, shares at Jun. 30, 2013	174,960,000	174,960,000