Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2013

Stock option activity for the year ended December 31, 2013 is presented below (in thousands, except per share data and contractual term):


	Number of Shares			Weighted - Average Exercise Price Per Share		Weighted - Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Outstanding at December 31, 2012		1,936		$	29.03
Granted		531			35.34
Exercised		(626	)		25.93
Forfeited		(107	)		32.86

Outstanding at December 31, 2013		1,734		$	31.85		7.05	$	11,129

Exercisable at December 31, 2013		784		$	28.80		5.06	$	7,416

Vested and expected to vest at December 31, 2013		1,663		$	31.73		6.97	$	10,878

Details of Restricted Stock Units (RSU) Activity

RSU activity for the year ended December 31, 2013 is presented below (in thousands, except per share data):


	Number of Shares			Weighted- Average Grant Date Fair Value
Unvested at December 31, 2012		301		$	32.98
Granted		207			34.58
Vested		(67	)		32.91
Forfeited		(69	)		31.60

Unvested at December 31, 2013		372		$	34.14

Summary of Shares Purchased by Employees Under the Stock Purchase Plan

Prior to 2012 purchase periods commenced on each successive January 1 and July 1. Shares purchased by employees under the Stock Purchase Plan are as follows (in thousands, except per share data):


	Shares		Purchase
Purchase Period Ended	Purchased		Price
February 28. 2013		26	$	23.34
August 31, 2013		27	$	23.42
August 31, 2012		23	$	24.88
June 30, 2011		51	$	28.02
December 31, 2011		50	$	28.08