XML 83 R42.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stock-Based Compensation (Tables)
 12 Months Ended
Dec. 31, 2019
Share-based Payment Arrangement [Abstract]  
Stock-Based Compensation
Stock-based compensation is included in the following financial statement captions: 
 Year Ended December 31,
 201920182017
Cost of sales$9,249  $6,535  $5,863  
Sales and marketing3,815  2,550  2,041  
Research and development7,690  6,410  5,001  
General and administrative12,824  12,532  10,116  
Total stock-based compensation33,578  28,027  23,021  
Tax benefit recognized(5,114) (6,632) (7,367) 
Net stock-based compensation$28,464  $21,395  $15,654  
Summary of Stock Option Valuation Assumptions
The assumptions used in the Black-Scholes model for the calculation of compensation were as follows for the years ended December 31:
201920182017
Expected term
4.3 - 5.1 years
4.1 - 4.9 years
3.8 - 5.0 years
Volatility
37% - 38%
31% - 36%
31% - 35%
Risk-free rate of return
1.66% - 2.55%
2.54% - 3.01%
1.57% - 1.97%
Dividend yield0.25%  0.25%  0.25%  
Forfeiture rate—%  —%  —%  
Summary of Option Activity
The following table summarizes the option activity for the years ended December 31:
Number of
Options
Weighted-
Average
Exercise
Price
Weighted-
Average
Remaining
Contractual
Life
Aggregate
Intrinsic
Value
   (In years)(In thousands)
Outstanding — January 1, 20172,064,253  $60.65  
Granted293,284  124.57  
Exercised(546,931) 50.50  
Forfeited(13,113) 90.81  
Outstanding — December 31, 20171,797,493  73.95  6.02$251,970  
Granted257,111  232.26  
Exercised(282,720) 58.94  
Forfeited(24,810) 131.36  
Outstanding — December 31, 20181,747,074  98.93  5.80$58,084  
Granted334,740  153.78  
Exercised(192,533) 56.58  
Forfeited(46,839) 149.64  
Outstanding — December 31, 20191,842,442  $112.03  5.73$85,110  
Unvested — December 31, 2019797,960  $149.66  7.96$14,576  
Exercisable — December 31, 20191,044,482  $83.29  4.02$70,534  
Summary of Restricted Stock Unit Activity
The following table summarizes the restricted stock units ("RSU's") activity for the years ended December 31:
Number of
Shares
Weighted-Average Grant-Date Fair Value
Weighted-
Average
Remaining
Contractual
Life
Aggregate
Intrinsic
Value
   (In years)(In thousands)
Outstanding — January 1, 2017366,770  $79.72  
Granted106,764  127.29  
Vested(90,385) 66.18  
Canceled(4,888) 90.54  
Outstanding — December 31, 2017378,261  96.23  2.55$80,997  
Granted80,254  227.45  
Vested(97,997) 91.62  
Canceled(9,497) 121.37  
Outstanding — December 31, 2018351,021  126.93  2.62$39,767  
Granted120,090  151.94  
Vested(147,606) 120.58  
Canceled(16,667) 139.73  
Outstanding — December 31, 2019306,838  $139.09  2.57$44,467  
Summary of Performance Units Fair Value Assessment
The weighted-average fair value of the performance units was determined using the Monte Carlo simulation model incorporating the following weighted-average assumptions:
201920182017
Performance term3.0 years3.0 years3.0 years
Volatility
18% - 40%
13% - 32%
13% - 31%
Risk-free rate of return2.48%  2.41%  1.49%  
Dividend yield—%  —%  —%  
Weighted-average fair value per share$192.46  $284.78  $147.25  
Summary of Performance Stock Unit Activity
The following table summarizes the performance stock units ("PSU's") activity for the years ended December 31:
Number of
Shares
Weighted-Average Grant-Date Fair Value
Weighted-
Average
Remaining
Contractual
Life
Aggregate
Intrinsic
Value
   (In years)(In thousands)
Outstanding — January 1, 201754,505  $108.51  
Granted21,444  147.25  
Vested—  
Canceled—  
Outstanding — December 31, 201775,949  119.45  1.93$16,263  
Granted33,706  238.12  
Vested—  
Canceled—  
Outstanding — December 31, 2017109,655  146.96  1.77$12,423  
Granted34,989  190.83  
Vested(43,594) 128.54  
Canceled(1,208) 228.68  
Outstanding — December 31, 201999,842  $162.34  1.84$14,469