Stock-Based Compensation

9 Months Ended

Sep. 30, 2018

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

The Company’s stock-based compensation program is a long-term retention program that is intended to attract and reward talented employees and align stockholder and employee interests. As of September 30, 2018, the Company had one stock-based compensation plan under which it was granting equity awards. The Company is currently granting stock-based awards from its Amended and Restated 2014 Equity Incentive Plan (the "2014 Plan"), which was approved at the Company's Annual Meeting of Stockholders on June 22, 2017. In connection with certain of the Company’s acquisitions, the Company has assumed certain plans from acquired companies. The Company’s Board of Directors has provided that no new awards will be granted under the Company’s acquired stock plans. Awards previously granted under the Company's superseded stock plans that are still outstanding typically expire between five and ten years from the date of grant and will continue to be subject to all the terms and conditions of such plans, as applicable. The Company’s superseded stock plans with outstanding awards include the Amended and Restated 2005 Equity Incentive Plan ("2005 Plan").

Under the terms of the 2014 Plan, the Company is authorized to grant incentive stock options (“ISOs”), non-qualified stock options (“NSOs”), non-vested stock, non-vested stock units, stock appreciation rights (“SARs”), and performance units and to make stock-based awards to full and part-time employees of the Company and its subsidiaries or affiliates, where legally eligible to participate, as well as to consultants and non-employee directors of the Company. ISOs, NSOs, and SARs are not currently being granted. Currently, the 2014 Plan provides for the issuance of 46,000,000 shares of common stock. In addition, shares of common stock underlying any awards granted under the Company’s 2014 Plan or the 2005 Plan that are forfeited, canceled or otherwise terminated (other than by exercise) are added to the shares of common stock available for issuance under the 2014 Plan. Under the 2014 Plan, NSOs must be granted at exercise prices no less than fair market value on the date of grant. Non-vested stock awards may be granted for such consideration in cash, other property or services, or a combination thereof, as determined by the Company’s Compensation Committee of its Board of Directors. Stock-based awards are generally exercisable or issuable upon vesting. The Company’s policy is to recognize compensation cost for awards with only service conditions and a graded vesting schedule on a straight-line basis over the requisite service period for the entire award. As of September 30, 2018, there were 22,603,277 shares of common stock reserved for issuance pursuant to the Company’s stock-based compensation plans including authorization under its 2014 Plan to grant stock-based awards covering 16,927,000 shares of common stock.

In December 2014, the Company’s Board of Directors approved the 2015 Employee Stock Purchase Plan (the “2015 ESPP”), which was approved by stockholders at the Company’s Annual Meeting of Stockholders held on May 28, 2015. Under the 2015 ESPP, all full-time and certain part-time employees of the Company are eligible to purchase common stock of the Company twice per year at the end of a six-month payment period (a “Payment Period”). During each Payment Period, eligible employees who so elect may authorize payroll deductions in an amount no less than 1% nor greater than 10% of his or her base pay for each payroll period in the Payment Period. At the end of each Payment Period, the accumulated deductions are used to purchase shares of common stock from the Company up to a maximum of 12,000 shares for any one employee during a Payment Period. Shares are purchased at a price equal to 85% of the fair market value of the Company's common stock, on either the first business day of the Payment Period or the last business day of the Payment Period, whichever is lower. Employees who, after exercising their rights to purchase shares of common stock in the 2015 ESPP, would own shares representing 5% or more of the voting power of the Company’s common stock, are ineligible to continue to participate under the 2015 ESPP. The 2015 ESPP provides for the issuance of a maximum of 16,000,000 shares of common stock. As of September 30, 2018, 1,721,924 shares have been issued under the 2015 ESPP. The Company recorded stock-based compensation costs related to the 2015 ESPP of $1.8 million and $4.4 million for the three months ended September 30, 2018 and 2017, respectively, and $7.3 million and $7.9 million for the nine months ended September 30, 2018 and 2017, respectively.

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			Nine Months Ended
	September 30, 2018	September 30, 2017		September 30, 2018	September 30, 2017
Expected volatility factor	0.26 - 0.29	0.27 - 0.29		0.26 - 0.29	0.27 - 0.29
Risk free interest rate	1.63% - 2.19%	0.60% - 1.12%		1.12% - 2.19%	0.60% - 1.12%
Expected dividend yield	0% - 1.27%	0	%	0% - 1.27%	0	%
Expected life (in years)	0.5	0.5		0.5	0.5

The Company determined the expected volatility factor by considering the implied volatility in six-month market-traded options of the Company's common stock based on third-party volatility quotes. The Company's decision to use implied volatility was based upon the availability of actively traded options on the Company's common stock and its assessment that implied volatility is more representative of future stock price trends than historical volatility. The risk-free interest rate was based on a U.S. Treasury instrument whose term is consistent with the expected term of the stock options. The Company's historical dividend yield input was zero in prior periods as it has not historically paid cash dividends on its common stock. The current dividend yield has been updated for expected dividend yield payout given the Company's previously announced intent to pay a recurring quarterly dividend beginning in December 2018. The expected term is based on the term of the purchase period for grants made under the ESPP.

Stock-Based Compensation

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, 2018		September 30, 2017		September 30, 2018		September 30, 2017
Cost of subscription, support and services	$	2,106	$	1,132	$	5,827	$	2,539
Research and development	17,009		14,365		45,517		35,691
Sales, marketing and services	18,910		16,063		52,095		42,388
General and administrative	14,714		20,172		40,867		46,601
Total	$	52,739	$	51,732	$	144,306	$	127,219

Non-vested Stock Units

Market Performance and Service Condition Stock Units

In March 2017, the Company granted senior level employees non-vested stock unit awards representing, in the aggregate, 275,148 non-vested stock units that vest based on certain target performance and service conditions. The number of non-vested stock units underlying the award will be determined within sixty days of the three-year performance period ending December 31, 2019. The attainment level under the award will be based on the Company's relative total return to stockholders over the performance period compared to a pre-established custom index group. If the Company’s relative total return to stockholders is between the 41st percentile and the 80th percentile when compared to the index companies, the number of non-vested stock units earned will be based on interpolation. The maximum number of non-vested stock units that may vest pursuant to the awards is capped at 200% of the target number of non-vested stock units set forth in the award agreement and is earned if the Company's relative total return to stockholders when compared to the index companies is at or greater than the 80th percentile. If the Company’s total return to stockholders is negative, the number of non-vested stock units earned will be no more than 100% regardless of the Company’s relative total return to stockholders compared to the index companies. If the awardee is not employed by the Company at the end of the performance period, the extent to which the awardee will vest in the award, if at all, is dependent upon the timing and character of the termination as provided in the award agreement. Each non-vested stock unit, upon vesting, represents the right to receive one share of the Company's common stock.

The market condition requirements are reflected in the grant date fair value of the award, and the compensation expense for the award will be recognized assuming that the requisite service is rendered regardless of whether the market conditions are achieved. 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	%

For the March 2017 grant, the range of expected volatilities utilized was based on the historical volatilities of the Company's common stock and the average of its peer group. The Company chose to use historical volatility to value these awards because historical stock prices were used to develop the correlation coefficients between the Company and its peer group in order to model the stock price movements. The volatilities used were calculated over the most recent 2.75 year period, which is commensurate with the awards' performance period at the grant date. The risk free interest rate was based on the implied yield available on U.S. Treasury zero-coupon issues with remaining terms equivalent to the performance period. In addition, the Company used a dividend yield of zero in its model. The estimated fair value of each award as of the date of grant was $104.05.

Service-Based Stock Units

The Company also awards senior level employees, certain other employees and new non-employee directors, non-vested stock units granted under the 2014 Plan that vest based on service. The majority of these non-vested stock unit awards generally vest 33.33% on each anniversary subsequent to the date of the award. The Company also assumes non-vested stock units in connection with certain of its acquisitions. The assumed awards have the same three-year vesting schedule. Each non-vested stock unit, upon vesting, represents the right to receive one share of the Company’s common stock. In addition, the Company awards non-vested stock units to all of its continuing non-employee directors. These awards vest monthly in 12 equal installments based on service and, upon vesting, each stock unit represents the right to receive one share of the Company's common stock.

Company Performance Stock Units

In March 2018, the Company awarded senior level employees non-vested performance stock unit awards granted under the 2014 Plan. The number of non-vested stock units underlying the award will be determined within sixty days following completion of the performance period ending December 31, 2020 and will be based on the achievement of specific corporate financial performance goals related to subscription bookings as a percentage of total product bookings measured during the period from January 1, 2020 to December 31, 2020. As defined in the applicable award agreements, total product bookings includes subscription bookings. The number of non-vested stock units issued will be based on a graduated slope, with the maximum number of non-vested stock units issuable pursuant to the award capped at 200% of the target number of non-vested stock units set forth in the award agreement. The Company is required to estimate the attainment expected to be achieved related to the defined performance goals and the number of non-vested stock units that will ultimately be awarded in order to recognize compensation expense over the vesting period. Each non-vested stock unit, upon vesting, represents the right to receive one share of the Company’s common stock. Compensation expense will be recorded through the end of the performance period on December 31, 2020 if it is deemed probable that the performance goals will be met. If the performance goals are not met, no compensation cost will be recognized and any previously recognized compensation cost will be reversed.

On August 1, 2017, the Company awarded certain senior level employees non-vested performance stock units granted under the 2014 Plan. The number of non-vested stock units underlying each award will be determined within sixty days following completion of the performance period ending December 31, 2019 and will be based on achievement of specific corporate financial performance goals related to non-GAAP net operating margin and subscription bookings as a percent of total product bookings measured during the period from January 1, 2019 to December 31, 2019. As defined in the applicable award agreements, total product bookings includes subscription bookings. The number of non-vested stock units issued will be based on a graduated slope, with the maximum number of non-vested stock units issuable pursuant to the award capped at 200% of the target number of non-vested stock units set forth in the award agreement. The Company is required to estimate the attainment expected to be achieved related to the defined performance goals and the number of non-vested stock units that will ultimately be awarded in order to recognize compensation expense over the vesting period. Each non-vested stock unit, upon vesting, represents the right to receive one share of the Company’s common stock. The non-GAAP net operating margin and subscription bookings as a percent of total product bookings targets were set in the first quarter of 2018. As a result, such awards were not outstanding under U.S. GAAP until the first quarter of 2018 when the performance goals were determined and subsequently communicated to employees who received the awards. Compensation expense will be recorded through the end of the performance period on December 31, 2019 if it is deemed probable that the performance goals will be met. If the performance goals are not met, no compensation cost will be recognized and any previously recognized compensation cost will be reversed.

Unrecognized Compensation Related to Stock Units

As of September 30, 2018, the total number of non-vested stock units outstanding, including company performance awards, market performance and service condition awards and service-based awards, including service-based awards assumed in connection with acquisitions, was 5,628,216. As of September 30, 2018, there was $349.0 million of total unrecognized compensation cost related to non-vested stock units. The unrecognized cost is expected to be recognized over a weighted-average period of 1.77 years.