Basic and Diluted Earnings Per Share

3 Months Ended

Mar. 31, 2012

Basic and Diluted Earnings Per Share [Abstract]

Basic and Diluted Earnings Per Share

Note 9.  Basic and Diluted Earnings Per Share

Basic earnings per share of common stock is computed using the weighted average number of shares of common stock outstanding during each period. The diluted earnings per share of common stock include the effect of outstanding stock options, shares of restricted stock, or shares of our common stock held in a rabbi trust (when dilutive). The following table summarizes the calculation of basic and diluted earnings per share:

	Three Months Ended March 31,
	2012		2011
(millions, except per share amounts)
Net Income	$	263	$	14
Weighted Average Number of Shares Outstanding, Basic		177		176
Incremental Shares From Assumed Conversion of Dilutive Stock Options and Restricted Stock		3		2
Weighted Average Number of Shares Outstanding, Diluted		180		178
Earnings Per Share, Basic	$	1.48	$	0.08
Earnings Per Share, Diluted		1.47		0.08
Number of antidilutive stock options, shares of restricted stock and shares of common stock in rabbi trust excluded from calculation above		2		2