Consolidated Statements of Changes in Equity (Unaudited) (USD $) In Millions, except Share data	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Dec. 31, 2010	$ 4,009	$ 1,386	$ 1,810	$ 829	$ (16)
Beginning Balance, shares at Dec. 31, 2010	138,632,324	139,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	347			347
Dividends declared on common stock	(229)			(229)
Benefit obligations, net of tax	1				1
Ending Balance at Sep. 30, 2011	$ 4,128	$ 1,386	$ 1,810	$ 947	$ (15)
Ending Balance, shares at Sep. 30, 2011	138,632,324	139,000,000