Net income per common share (Notes)

12 Months Ended

Mar. 31, 2012

Earnings Per Share [Abstract]

Net income per common share

NET INCOME PER COMMON SHARE

The following table sets forth the computation of basic and diluted net income per common share from continuing operations (in thousands, except per share amounts):

	Year ended March 31,
	2012		2011		2010
Net income from continuing operations	$	336,705	$	429,167	$	217,005
Weighted average common shares outstanding	191,283		187,066		183,642
Dilutive effect of stock options and RSUs	4,207		4,463		3,697
Dilutive effect of convertible debt	8,029		3,186		—
Weighted average common and potential common shares outstanding	203,519		194,715		187,339
Basic net income per common share – continuing operations	$	1.76	$	2.29	$	1.18
Diluted net income per common share – continuing operations	$	1.65	$	2.20	$	1.16

Diluted net income per common share for continuing operations for the years ended March 31, 2012 and 2011 includes 8,029,255 and 3,185,591 shares, respectively, issuable upon the exchange of debentures (see Note 14).  There were no shares issuable upon the exchange of the debentures for the year ended March 31, 2010. The debentures have no impact on diluted net income per common share unless the average price of the Company's common stock exceeds the conversion price because the principal amount of the debentures will be settled in cash upon conversion.  Prior to conversion, the Company will include, in the diluted net income per common share calculation, the effect of the additional shares that may be issued when the Company's common stock price exceeds the conversion price using the treasury stock method.  The weighted average conversion price per share used in calculating the dilutive effect of the convertible debt for years ended March 31, 2012, 2011 and 2010 was $28.50, $29.61 and $31.16, respectively.

Diluted net loss per common share from discontinued operations for the year ended March 31, 2011 was $0.05. There was no diluted net income or loss from discontinued operations for the years ended March 31, 2012 or 2010.

Weighted average common shares exclude the effect of option shares which are not dilutive.  For the years ended March 31, 2012, 2011 and 2010, the number of option shares that were antidilutive were 53,374, 132,084 and 4,109,841, respectively.