Earnings Per Common Share

6 Months Ended

Jun. 30, 2011

Earnings Per Common Share

Earnings Per Common Share

9. Earnings Per Common Share

Basic earnings per common share (EPS) are computed by dividing net income by the weighted-average number of shares of common stock outstanding.  For purposes of calculating diluted EPS, net income is adjusted for the after-tax amount of interest and deferred financing costs associated with our convertible debt, and the denominator reflects the potential dilution that could occur if stock options, unvested restricted stock or other contracts to issue common stock were exercised or converted into common stock, using the treasury stock method, as well as the potential dilution if the remaining convertible notes were converted to common stock. 

The following table summarizes the calculation of basic and diluted EPS for the three and six months ended June 30, 2011 and 2010:

	Three months ended		Six months ended
	June 30,		June 30,
	2011	2010	2011	2010
Net income used for basic calculation	$     34,745	$     21,773	$     61,575	$     42,707
Weighted-average effect of dilutive securities:
Interest expense and debt financing cost amortization, net of tax,  related to our 1.375% convertible senior notes	4	11	16	52
Net income used for diluted calculation	34,749	21,784	61,591	42,759
Shares used in computing earnings per common share—basic	182,962	178,004	182,347	177,510
Weighted-average effect of dilutive securities:
Shares issuable upon the assumed conversion of our 1.375% convertible senior notes	138	904	305	1,062
Stock awards	8,087	6,242	8,138	6,108
Dilutive potential common shares	8,225	7,146	8,443	7,170
Shares used in computing earnings per common share—diluted	191,187	185,150	190,790	184,680
Earnings per common share:
Basic	$         0.19	$         0.12	$         0.34	$         0.24
Diluted	$         0.18	$         0.12	$         0.32	$         0.23

The following table represents the potentially dilutive shares excluded from the calculation of EPS for the three and six months ended June 30, 2011 and 2010 because their effect is anti-dilutive:

	Three months ended		Six months ended
	June 30,		June 30,
	2011	2010	2011	2010
Potentially dilutive securities:
Options to purchase common stock	2,142	2,998	1,723	2,622
Unvested restricted stock	9	8	10	10
	2,151	3,006	1,733	2,632