2. Net Income per Share



	Three Months Ended				Nine Months Ended
	September 30,				September 30,
Net Income per Basic and Diluted Share:	2013		2012		2013		2012
(in thousands except per share amounts)
Numerator
Net income used to compute net income per basic share	$	56,225	$	48,575	$	203,438	$	162,261
Add back interest expense for convertible notes, net of estimated tax of approximately $7 and $4 for the three months ended September 30, 2013 and 2012, respectively, and $13 and $21 for the nine months ended September 30, 2013 and 2012, respectively (see Note 9)	12		6		25		40
Net income used to compute net income per diluted share	$	56,237	$	48,581	$	203,463	$	162,301

Denominator
Total weighted-average shares used to compute net income per basic share	139,848		139,715		139,830		139,693
Restricted stock outstanding	80		110		76		93
Effect of dilutive stock options	20		18		19		16
Assumed conversion of Series 2012 Notes	9,674		7,008		10,141		7,427
Assumed conversion of May 2015 Notes	4,910		2,609		5,160		2,825
Assumed conversion of February 2015 Notes	61		166		140		624
Weighted-average shares used to compute net income per diluted share	154,593		149,626		155,366		150,678

Net income per basic share	$	0.40	$	0.35	$	1.45	$	1.16
Net income per diluted share	$	0.36	$	0.32	$	1.31	$	1.08

We compute net income per basic share using the weighted-average number of shares of common stock outstanding during the period less the weighted-average number of restricted stock shares that are subject to repurchase by the Company.

We compute net income per diluted share using the sum of the weighted-average number of common and common equivalent shares outstanding. Common equivalent shares used in the computation of net income per diluted share include shares that may be issued under our stock options and restricted stock awards, our February 2015 Notes, our Series 2012 Notes and our May 2015 Notes on a weighted average basis for the period that the notes were outstanding, including the effect of adding back interest expense and the underlying shares using the if-converted method. In the first quarter of 2012, $179.0 million aggregate principal of our February 2015 Notes was exchanged for our Series 2012 Notes, and in the third quarter of 2013, $1.0 million aggregate principal of our February 2015 Notes was exchanged for our Series 2012 Notes, and the February 2015 Notes were retired.

In May 2011, we issued our May 2015 Notes, and in January and February 2012, we issued our Series 2012 Notes. The Series 2012 Notes and May 2015 Notes are net share settled, with the principal amount settled in cash and the excess settled in our common stock. The weighted average share adjustments related to our Series 2012 Notes and May 2015 Notes, shown in the table above, include the shares issuable in respect of such excess.

We excluded from our calculations of net income per diluted share 20.8 million and 19.2 million shares for our warrants for the three months ended September 30, 2013 and 2012, respectively, and 20.8 million and 19.2 million shares for the nine months ended September 30, 2013 and 2012, respectively, for warrants issued in 2011, because the exercise price of the warrants exceeded the VWAP of our common stock and thus, for the periods presented, no stock was issuable upon conversion. These securities could be dilutive in future periods. Our purchased call options, issued in 2011, will always be anti-dilutive and therefore 24.4 million and 22.6 million shares were excluded from our calculations of net income per diluted share for the three months ended September 30, 2013 and 2012, respectively, and 24.4 million and 22.6 million shares were excluded for the nine months ended September 30, 2013 and 2012, respectively, because they have no effect on diluted net income per share. For information related to the conversion rates on our convertible debt, see Note 9.

For the three months ended September 30, 2013, we excluded approximately 121,000 and 10,000 shares underlying outstanding stock options and restricted stock awards, respectively, and for the nine months ended September 30, 2013, we excluded approximately 133,000 and zero shares underlying outstanding stock options and restricted stock awards, respectively, calculated on a weighted average basis, from our net income per diluted share calculations because their effect was anti-dilutive.

For the three and nine months ended September 30, 2012, we excluded approximately 144,000 and 164,000 shares underlying outstanding stock options, calculated on a weighted average basis, from our net income per diluted share calculations because their effect was anti-dilutive.