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, 2011	$ 7,053	$ 3,417	$ 3,750	$ (158)	$ 44	$ 7,053
Beginning Balance, shares at Dec. 31, 2011	169,247,282	169,247,000
Net Income	305		302			305
Net Income (Loss) Attributable to Noncontrolling Interest	3				3
Dividends declared on common stock			(307)			(307)
Stock Issued During Period, Shares, New Issues		363,000
Stock Issued During Period, Value, New Issues		20				20
Contribution of Common Stock to Pension Plan Shares	1,300,000	1,335,000
Contribution of Common Stock to Pension Plan	80	80
Benefit obligations, net of tax	6			6		6
Net change in unrealized losses on investments, net of tax				1		1
Stock-based compensation, distributions to noncontrolling interests and other, shares		810,000
Stock-based compensation, distributions to noncontrolling interests and other		32				26
Stockholders' Equity, Other			(1)
Payments of Ordinary Dividends, Noncontrolling Interest					(5)
Ending Balance at Jun. 30, 2012	$ 7,184	$ 3,549	$ 3,744	$ (151)	$ 42	$ 7,184
Ending Balance, shares at Jun. 30, 2012	171,754,812	171,755,000