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
Beginning Balance at Dec. 31, 2011	$ 7,053	$ 3,417	$ 3,750	$ (158)	$ 44
Beginning Balance, shares at Dec. 31, 2011	169,247,282	169,247,000
Net Income	535		529
Net Income (Loss) Attributable to Noncontrolling Interest	6				6
Dividends declared on common stock	(307)		(307)
Stock Issued During Period, Shares, New Issues		521,000
Stock Issued During Period, Value, New Issues	29	29
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	9			9
Net change in unrealized losses on investments, net of tax	1			1
Foreign currency translation, net of tax	1			1
Stock-based compensation, distributions to noncontrolling interests and other, shares		970,000
Stock-based compensation, distributions to noncontrolling interests and other	30	41
Stockholders' Equity, Other			(3)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders					(8)
Ending Balance at Sep. 30, 2012	$ 7,431	$ 3,567	$ 3,969	$ (147)	$ 42
Ending Balance, shares at Sep. 30, 2012	172,073,378	172,073,000