Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2016

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

Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions

The Company used the Black-Scholes model to estimate the fair value of its Employee Stock Purchase Plan awards with the following weighted-average assumptions:

	Three Months Ended				Nine Months Ended
	September 30, 2016		September 30, 2015		September 30, 2016		September 30, 2015
Expected volatility factor	0.27 - 0.41		0.35		0.27 - 0.41		0.35
Risk free interest rate	0.35% - 0.42%		0.25	%	0.25% - 0.42%		0.25	%
Expected dividend yield	0	%	0	%	0	%	0	%
Expected life (in years)	0.5		0.5		0.5		0.5

Schedule of Total Stock-based Compensation Recognized by Income Statement Classification

The detail of the total stock-based compensation recognized by income statement classification is as follows (in thousands):

	Three Months Ended				Nine Months Ended
Income Statement Classifications	September 30, 2016		September 30, 2015		September 30, 2016		September 30, 2015
Cost of services and maintenance revenues	$	911	$	803	$	2,561	$	2,095
Research and development	13,256		9,118		35,878		31,454
Sales, marketing and services	14,848		16,922		41,442		38,083
General and administrative	19,267		11,828		56,321		32,042
Total	$	48,282	$	38,671	$	136,202	$	103,674

Schedule of Assumptions Used to Value Nonvested Share Grants

The grant date fair value of the non-vested performance stock unit awards was determined through the use of a Monte Carlo simulation model, which utilized multiple input variables that determined the probability of satisfying the market condition requirements applicable to each award as follows:

	March 2016 Grant		January 2016 Grant		March 2015 Grant
Expected volatility factor	0.29 - 0.39		0.29 - 0.37		0.14 - 0.29
Risk free interest rate	0.91	%	1.10	%	0.85	%
Expected dividend yield	0	%	0	%	0	%