Net Income per Common Share (Tables)

3 Months Ended

Mar. 31, 2012

Net Income per Common Share

Computation of basic and diluted earnings per share

	Three Months Ended March 31,
	2011		2012
Numerator:
Net income	$	34,298	$	20,790
Denominator:
Weighted average number of common shares outstanding—basic		33,051		27,199
Common stock equivalents—stock options		493		432
Common stock equivalents—restricted stock awards		15		13
Common stock equivalents—restricted stock units		97		102
Common stock equivalents—employee stock purchase plan		—		1
Weighted average number of common shares outstanding—diluted		33,656		27,747
Net income per common share—basic	$	1.04	$	0.76
Net income per common share—diluted	$	1.02	$	0.75