Net Income per Common Share (Tables)

9 Months Ended

Sep. 30, 2013

Net Income per Common Share

Computation of basic and diluted earnings per share

        The following tables reconcile income (numerator) and shares (denominator) used in the computations of net income per common share (in thousands, except per share data):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2012		2013		2012		2013
Numerator:
Net income	$	66,262	$	47,232	$	114,025	$	106,770
Denominator:
Weighted average number of common shares outstanding—basic		27,521		26,990		27,346		26,976
Common stock equivalents—stock options		426		655		395		539
Common stock equivalents—restricted stock		7		4		10		11
Common stock equivalents—restricted stock units		87		54		83		35
Common stock equivalents—employee stock purchase plan		1		1		1		2
Weighted average number of common shares outstanding—diluted		28,042		27,704		27,835		27,563
Net income per common share—basic	$	2.41	$	1.75	$	4.17	$	3.96
Net income per common share—diluted	$	2.36	$	1.70	$	4.10	$	3.87