NET INCOME PER SHARE

The Company computes basic net income per share by dividing net income by the weighted average number of common shares outstanding during the period. Diluted net income per share is based upon the weighted average number of common and common equivalent shares outstanding during the period.

Common equivalent shares related to stock options, restricted stock, restricted stock units, and performance share units are calculated using the treasury stock method. Performance share units are included in the weighted average common equivalent shares based on the number of shares that would be issued if the end of the reporting period were the end of the performance period, if the result would be dilutive.

The Company’s convertible debt issues have net share settlement features requiring the Company upon conversion to settle the principal amount of the debt for cash and the conversion premium for cash or shares of the Company’s common stock. The convertible notes are included in the calculation of diluted net income per share if their inclusion is dilutive under the treasury stock method.

A reconciliation of the weighted average number of shares outstanding used in calculating diluted earnings per share is as follows (in thousands):



	For the Year Ended December 31,
	2012	2011	2010
Weighted average number of basic common shares outstanding	49,840	49,654	47,955
Weighted average dilutive stock options, restricted stock units and performance share units	501	828	1,628
Assumed conversion of Convertible Senior Notes	985	729	1,405
Weighted average number of diluted common and common equivalent shares outstanding	51,326	51,211	50,988
Anti-dilutive potential common shares	2,202	1,453	2,487

Anti-dilutive potential common shares for the years ended December 31, 2012, 2011 and 2010 include approximately 2.0 million, 1.2 million shares and 1.9 million shares, respectively, that could be issued under the Company’s convertible debt if the Company experiences substantial increases in its common stock price. Under the treasury stock method, the convertible notes will generally have a dilutive impact on net income per share if the Company’s average stock price for the period exceeds the conversion price for the convertible notes.

In 2006, the Company issued $172.5 million aggregate principal amount of convertible notes due September 30, 2013 (the "2013 Notes"). In 2006, the Company also entered into hedge transactions (the "Conversion Spread Hedges") relating to the potential dilution of the Company's common stock upon conversion of the 2013 Notes at their stated maturity date. Under the Conversion Spread Hedges, the Company is entitled to purchase from Goldman Sachs and Merrill Lynch a total of approximately 4.3 million shares of the Company's common stock (the number of shares underlying the 2013 Notes) at a strike price of $40.38 per share (subject to adjustment in certain circumstances) in 2013, and the counterparties are entitled to purchase from the Company a total of approximately 4.3 million shares of the Company's common stock at a strike price of $50.47 per share (subject to adjustment in certain circumstances) in 2013.

The 2013 Notes were converted prior to maturity. Therefore, upon early conversion of the 2013 Notes, the Company delivered any related conversion premium in shares of stock or a combination of shares or cash. The Conversion Spread Hedges are separate transactions entered into by the Company and are not part of the terms of the 2013 Notes. The Conversion Spread Hedges did not immediately hedge against the associated dilution from early conversions of the 2013 Notes. Because of this timing difference, the number of shares, if any, that the Company receives from the Conversion Spread Hedges can differ materially from the number of shares that it delivered to the holders of the 2013 Notes upon their early conversion. The actual number of shares to be received will depend upon the Company's stock price on the date the Conversion Spread Hedges are exercisable, which coincides with the scheduled maturity of the 2013 Notes. The Conversion Spread Hedges are outstanding at December 31, 2012. However, since the beneficial impact of the Conversion Spread Hedges was anti-dilutive, it was excluded from the calculations of net income per share.

In 2006, the Company also issued in a private placement $172.5 million aggregate principal amount of Convertible Senior Notes due September 30, 2011 (the "2011 Notes"). The remaining outstanding principal amount at December 31, 2009 for these 2011 Notes was converted during 2010. Also in 2006, the Company entered into hedge transactions relating to the potential dilution of the Company's common stock upon conversion of the 2011 Notes. During the year ended December 31, 2010, the Company and the counterparties agreed to terminate the Conversion Spread Hedges associated with