Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Stock-Based Compensation Expense

Stock-based compensation expense related to stock options, ESPP purchase rights, and RSUs for the three months ended March 31, 2016 and 2015 is summarized as follows (in thousands):

	Three months ended March 31,
	2016			2015
Employee stock options	$	(45	)	$	34
RSUs		10,836			7,679
ESPP		766			1,179
Total stock-based compensation		11,557			8,892
Income tax benefit		(2,659	)		(1,979	)
Stock-based compensation expense, net of tax	$	8,898		$	6,913

Schedule of ESPP Purchase Rights and Underlying Weighted Average Assumptions

Stock options were not granted during the three months ended March 31, 2016 and 2015. The estimated weighted average fair value per share of ESPP purchase rights issued and the underlying weighted average assumptions for the three months ended March 31, 2016 and 2015 are as follows:

	Three months ended March 31,
	2016			2015
Weighted average fair value per share	$	10.39		$	10.17
Expected volatility		22% - 25	%		26% - 28	%
Risk-free interest rate		0.5% - 0.8	%		0.1% - 0.5	%
Expected term (in years)		0.5 - 2.0			0.5 - 2.0

Schedule of Stock Options Outstanding and Exercisable

Stock options outstanding and exercisable, including performance-based and market-based options, as of March 31, 2016 and activity for the three months ended March 31, 2016 are summarized below (in thousands, except weighted average exercise price and remaining contractual term):

	Shares outstanding			Weighted average exercise price		Weighted average remaining contractual term (years)		Aggregate intrinsic value
Options outstanding at January 1, 2016		443		$	13.20
Options forfeited and expired		(12	)		10.77
Options exercised		(1	)		16.57
Options outstanding at March 31, 2016		430		$	13.25		1.89	$	12,518
Options vested and expected to vest at March 31, 2016		430		$	13.25		1.89	$	12,518
Options exercisable at March 31, 2016		430		$	13.25		1.89	$	12,518

Schedule of Non-Vested RSUs

Non-vested RSUs, including performance-based and market-based RSUs, as of March 31, 2016 and activity during the three months ended March 31, 2016 are summarized below (shares in thousands):

	Shares			Weighted average grant date fair value
Non-vested at January 1, 2016		1,814		$	40.53
Restricted stock granted		412			38.96
Restricted stock vested		(251	)		37.00
Restricted stock forfeited		(217	)		38.85
Non-vested at March 31, 2016		1,758		$	40.87

Schedule of Performance-Based and Market-Based RSUs and Stock Options

Performance-based and market-based RSUs and stock options included in the tables above as of March 31, 2016 and activity for the three months ended March 31, 2016 are summarized below (in thousands):

	Performance-based						Market-based
	RSUs			Stock Options			RSUs
Non-vested at December 31, 2015		920			16			23
Granted		343			—			—
Vested		(211	)		(4	)		—
Forfeited		(195	)		(12	)		—
Non-vested at March 31, 2016		857			—			23

Schedule of Weighted Average Grant Date Fair Value Per Share of Performance-Based RSUs and Assumptions Used to Estimate Fair Value

The weighted average grant date fair value per share of performance-based RSUs granted and the assumptions used to estimate grant date fair value for the three months ended March 31, 2016 and 2015 are as follows:

	Performance-based
	RSUs
	Short-term		Long-term
Three months ended March 31, 2015 Grants
Grant date fair value per share	$	39.47	$	36.78
Service period (years)		1.0		3.0
Three months ended March 31, 2015 Grants
Grant date fair value per share	$	37.00	$	38.64
Service period (years)		1.0		2.0