Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2014

Presented below is a summary of our stock option activity for the nine months ended September 30, 2014 (in thousands, except for weighted average exercise price and weighted average remaining contractual terms):

	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Terms	Aggregate Intrinsic Value
Outstanding at December 31, 2013	4,273		$	17.53	4.86	$	27,099
Granted	193		20.17
Exercised	(297	)	9.31
Forfeited	(254	)	23.40
Expired	(167	)	22.27
Outstanding at September 30, 2014	3,748		17.78		4.31	15,613
Expected to vest at September 30, 2014	1,796		22.72		5.86	402
Exercisable at September 30, 2014	1,910		$	13.02	2.82	$	15,198

Schedule of weighted -average assumptions used for estimating fair value of each stock option grant on the date of grant

	Nine months ended September 30,
	2014	2013
Expected dividend yield	—	—
Risk-free interest rate	1.56%	0.67%
Expected volatility	38.11%	40.05%
Expected life	4.81 years	4.47 years

Summary of status of restricted stock units

A summary of the status of our restricted stock units and of changes in restricted stock units outstanding under the 2006 Stock Plan for the nine months ended September 30, 2014 is as follows (in thousands, except for weighted average grant date fair value per unit):

	Number of Units		Weighted Average Grant Date Fair Value per Unit		Aggregate Intrinsic Value
Outstanding balance at December 31, 2013	636		$	25.50	$	14,429
Granted	261		20.21
Vesting of restricted stock units, net of shares withheld for taxes	(45	)	25.60
Shares withheld for taxes	(25	)	25.60
Forfeitures	(131	)	25.04
Outstanding balance at September 30, 2014	696		$	23.56	$	13,112

Summary of status of restricted stock awards

A summary of the status of our restricted stock awards at September 30, 2014 and of changes in restricted stock awards outstanding under the 2006 Stock Plan for the nine months ended September 30, 2014 is as follows (in thousands, except for weighted average grant date fair value per share):

	Shares		Weighted Average Grant Date Fair Value per Share		Aggregate Intrinsic Value
Outstanding balance at December 31, 2013	82		$	10.42	$	1,851
Granted	—		—
Vesting of restricted stock awards	(54	)	10.42
Shares withheld for payment of taxes upon vesting of restricted stock awards	(28	)	10.42
Forfeitures	—		—
Outstanding balance at September 30, 2014	—		$	—	$	—