Consolidated Statements of Changes in Equity (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, 2008		$ 3,175	$ 2,985	$ (165)	$ 43	$ 6,038
Beginning Balance, shares at Dec. 31, 2008		163,020,000
Net Income	535		532			535
Net Income (Loss) Attributable to Noncontrolling Interest	3				3
Dividends declared on common stock			(349)			(349)
Stock Issued During Period, Shares, New Issues		1,109,000
Issuance of common stock, value		35				35
Benefit obligations, net of tax	7			7		7
Foreign currency translation, net of tax	2			2		2
Net change in unrealized losses on derivatives, net of tax	3			1		1
Net change in unrealized losses on investments, net of tax	5			8		8
Contributions from NonControlling Interests					4	4
Stock-based compensation, distributions to noncontrolling interests and other, shares		1,271,000
Stock-based compensation, distributions to noncontrolling interests and other		47				35
Payments of Dividends, Noncontrolling Interest					(12)
Ending Balance at Dec. 31, 2009		3,257	3,168	(147)	38	6,316
Ending Balance, shares at Dec. 31, 2009		165,400,000
Net Income	639
Net Income (Loss) Attributable to Noncontrolling Interest	9				9
Stock Issued During Period, Shares, New Issues		777,000
Issuance of common stock, value	3,440	36				36
Benefit obligations, net of tax	15			15		15
Foreign currency translation, net of tax	1			1		1
Net change in unrealized losses on derivatives, net of tax	1			2		2
Net change in unrealized losses on investments, net of tax	(10)			(20)		(20)
Stock-based compensation, distributions to noncontrolling interests and other, shares		1,027,000
Stock-based compensation, distributions to noncontrolling interests and other		47				45
Payments of Dividends, Noncontrolling Interest					(2)
Contribution of Common Stock to Pension Plan Shares		2,224,000
Contribution of Common Stock to Pension Plan		100				100
Ending Balance at Dec. 31, 2010	6,767	3,440		(149)	45	6,767
Ending Balance, shares at Dec. 31, 2010	169,428,406	169,428,000
Beginning Balance at Sep. 30, 2010
Net Income			630			639
Dividends declared on common stock			(367)			(367)
Issuance of common stock, value						36
Contribution of Common Stock to Pension Plan						100
Ending Balance at Dec. 31, 2010	6,767	3,440	3,431	(149)	45	6,767
Beginning Balance, shares at Dec. 31, 2010	169,428,406	169,428,000
Net Income	720		711			720
Net Income (Loss) Attributable to Noncontrolling Interest	9
Dividends declared on common stock			(392)			(392)
Issuance of common stock, value	3,417
Benefit obligations, net of tax	(9)			(9)		(9)
Foreign currency translation, net of tax	0
Net change in unrealized losses on derivatives, net of tax	0
Net change in unrealized losses on investments, net of tax	0
Stock-based compensation, distributions to noncontrolling interests and other, shares		1,003,000
Stock-based compensation, distributions to noncontrolling interests and other		35				25
Payments of Dividends, Noncontrolling Interest					(10)
Stock Repurchased and Retired During Period, Shares		(1,184,000)
Repurchase of common stock		(58)				(58)
Ending Balance at Dec. 31, 2011	$ 7,053	$ 3,417	$ 3,750	$ (158)	$ 44	$ 7,053
Ending Balance, shares at Dec. 31, 2011	169,247,282	169,247,000