The following table sets forth the computation of basic and diluted shares for the periods indicated (amounts in thousands):

				Year Ended December 31,
				2012	2011	2010

Shares used in basic earnings per share calculation				54,738	56,669	60,361
	Effect of dilutive securities:
		Stock options		378	727	874
		Restricted stock units		424	564	557
		Performance-based restricted stock units		-	3	-
			Total effects of dilutive securities	802	1,294	1,431
Shares used in dilutive earnings per share calculation				55,540	57,963	61,792

For the years ended December 31, 2012, 2011 and 2010, 0.1 million, 0.1 million and 0.1 million, respectively, of options to purchase shares of common stock were outstanding but not included in the computation of diluted net income per share because the exercise price exceeded the value of the shares and the effect would have been anti-dilutive. For the years ended December 31, 2012, 2011 and 2010, restricted stock units of 0.8 million, 0.6 million, and 1.1 million, respectively, were outstanding but not included in the computation of diluted net income per share because the effect would have been anti-dilutive. For the years ended December 31, 2012, 2011 and 2010, there were no performance-based restricted stock units outstanding but not included in the computation of diluted net income per share. For the years ended December 31, 2012, 2011 and 2010, restricted stock units that vest based on the Company achieving specified operating income performance targets of 0.1 million, 0.1 million and 0.1 million, respectively, were outstanding but not included in the computation of diluted net income per share because they were determined not to be contingently issuable.