Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2018

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 2015 ESPP awards with the following weighted-average assumptions:

	Three Months Ended
	March 31, 2018		March 31, 2017
Expected volatility factor	0.27 - 0.29		0.29
Risk free interest rate	1.12% - 1.63%		0.60	%
Expected dividend yield	0	%	0	%
Expected life (in years)	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
Income Statement Classifications	March 31, 2018		March 31, 2017
Cost of subscription, support and services	$	1,480	$	592
Research and development	10,793		9,666
Sales, marketing and services	13,567		11,597
General and administrative	9,883		12,953
Total	$	35,723	$	34,808

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 2017 Grant
Expected volatility factor	0.27-0.32
Risk free interest rate	1.48	%
Expected dividend yield	0	%