Net income per common share (Tables)

12 Months Ended

Mar. 31, 2014

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 (in thousands, except per share amounts):

	Year ended March 31,
	2014		2013		2012
Net income	$	395,281	$	127,389	$	336,705
Weighted average common shares outstanding	198,291		194,595		191,283
Dilutive effect of stock options and RSUs	3,910		3,650		4,207
Dilutive effect of convertible debt	15,429		7,531		8,029
Weighted average common and potential common shares outstanding	217,630		205,776		203,519
Basic net income per common share	$	1.99	$	0.65	$	1.76
Diluted net income per common share	$	1.82	$	0.62	$	1.65