Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

Stock-Based Compensation Expense

This expense was allocated in the consolidated statements of comprehensive income (loss) as follows (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2017		2016		2017		2016
Cost of revenues	$	469	$	317	$	920	$	597
Operating expenses
Sales and marketing		574		639		1,091		1,293
Research and development		228		141		457		279
General and administrative		915		968		2,018		1,823
Total stock-based compensation expense	$	2,186	$	2,065	$	4,486	$	3,992

Stock Option Activity

Our stock option activity was as follows:

	Options			Weighted Average Exercise Price
	(#)			($/share)
Outstanding at December 31, 2016		1,016,012		$	44.72
Granted		167,903			56.00
Exercised		(60,592	)		20.52
Forfeited		(8,417	)		56.28
Outstanding at June 30, 2017		1,114,906			47.65

Weighted Average Grant Date Fair Value of Options Granted, Assumptions

The weighted average grant date fair value of options granted during the first six months of 2017 was $18.90 and this was estimated on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions:

Volatility	37.4	%
Dividend yield	0	%
Life (in years)	4.5
Risk-free interest rate	1.85	%

Fair Value Estimation of Common Stock Using Black-Scholes Option Pricing Model, Assumptions

The fair value was estimated based on the market price of our common stock at the beginning of the offering period using the Black-Scholes option pricing model with the following assumptions:

Volatility	26.0	%
Dividend yield	0	%
Life (in years)	0.5
Risk-free interest rate	0.62	%

Performance Share Units and Restricted Stock Units [Member]

Performance Share Units and Restricted Stock Units and Restricted Stock Awards

Activity for our performance share units and restricted stock units was as follows:

	Performance Share and Restricted Stock Units			Weighted Average Grant Date Fair Value
	(#)			($/share)
Outstanding at December 31, 2016		189,042		$	54.14
Granted		206,043			55.72
Vested and common stock issued		(64,818	)		53.63
Forfeited		(3,317	)		54.67
Outstanding at June 30, 2017		326,950			55.23

Restricted Stock Award [Member]

Performance Share Units and Restricted Stock Units and Restricted Stock Awards

Our restricted stock awards activity was as follows:

	Restricted Stock Awards			Weighted Average Grant Date Fair Value
	(#)			($/share)
Outstanding at December 31, 2016		1,524		$	52.28
Restricted common stock issued		5,454			58.29
Restrictions lapsed		(2,886	)		55.11
Forfeited		—			—
Outstanding at June 30, 2017		4,092			58.29