Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Tables)

v3.20.4
Summary of Significant Accounting Policies (Tables)
12 Months Ended
Dec. 31, 2020
Accounting Policies [Abstract]  
Calculation of Basic and Diluted Net Income Per Share
The following table reconciles share amounts utilized to calculate basic and diluted net income per share (in thousands, except per share data):
Year Ended December 31,
2020 2019 2018
Net income
$ 178,665  $ 59,229  $ 168,642 
Basic - weighted average common shares
17,600  17,260  17,952 
Dilutive effect of common stock equivalents
1,459  535  810 
Diluted - weighted average common shares
19,059  17,795  18,762 
Earnings per share:
Basic
$ 10.15  $ 3.43  $ 9.39 
Diluted
$ 9.37  $ 3.33  $ 8.99 
Anti-Dilutive Securities Excluded from Computation of Earnings Per Share
The calculation of dilutive shares excludes the effect of the following options that are considered anti-dilutive (in thousands):
Year Ended December 31,
2020 2019 2018
Anti-dilutive stock options
688  1,940  285 
Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan
The following table sets forth the stock-based compensation expense that we recognized for the periods indicated (in thousands):
2020 2019 2018
Stock-based compensation expense relating to:
Stock options $ 41,479  $ 40,936  $ 34,773 
Employee stock purchases
2,053  2,004  1,576 
Total stock-based compensation expense $ 43,532  $ 42,940  $ 36,349 
Stock-based compensation expense relating to:
Cost of revenues $ 3,707  $ 3,083  $ 2,955 
Sales and marketing
9,482  9,716  6,892 
Research and development 12,168  10,521  8,120 
General and administrative
18,175  19,620  18,382 
Total stock-based compensation expense $ 43,532  $ 42,940  $ 36,349 
Weighted Average Assumptions Used in Black-Scholes Valuation Model
The following are the weighted average assumptions used in the Black-Scholes-Merton option valuation model for the periods indicated:
2020 2019 2018
Expected dividend yield —  % —  % —  %
Risk-free interest rate 0.5  % 1.9  % 2.6  %
Expected volatility 87.3  % 73.6  % 50.2  %
Expected life (in years) 3.3 3.3 3.3