Equity and Noncontrolling Interests (Tables)

9 Months Ended

Sep. 30, 2011

Equity And Noncontrolling Interests [Abstract]

Common and Preferred Stock Dividends

	Common Stock		Convertible Preferred Stock
	($0.01/Share)		(4.99%/Year)
Amount paid for the nine months ended September 30, 2011	$	22	$	9
Amount paid in October 2011	$	7	$	—
Declared in October 2011:
Date of declaration	October 6, 2011			—
Payable to shareholders on record	December 2, 2011			—
Date payable	January 3, 2012			—

Components of net income attributable to noncontrolling interests

	Quarters Ended September 30,				Nine Months Ended September 30,
	2011		2010		2011		2010
	(In millions)
EPB	$	55	$	25	$	161	$	75
Preferred Stock of Cheyenne Plains (Note 15)		5		5		15		15
Preferred Stock of Ruby (Note 15)		15		11		50		11
Net income attributable to noncontrolling interests	$	75	$	41	$	226	$	101