Net income per common share (Tables)

12 Months Ended

Mar. 31, 2012

Earnings Per Share [Abstract]

Schedule computation of basic and diluted earnings per 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