XML 50 R37.htm IDEA: XBRL DOCUMENT v3.10.0.1
Equity Plans and Stock-Based Compensation (Tables)
12 Months Ended
Dec. 31, 2018
Share Based Compensation [Abstract]  
Option Activity under Stock-Based Compensation Plans

Activity under our stock plans is set forth below:

 

 

 

Shares Underlying

Outstanding Options

(in thousands)

 

 

Weighted-Average Exercise

Price Per Share

 

 

Weighted-Average

Remaining

Contractual Term

(years)

 

 

Aggregate

Intrinsic Value

(in thousands)

 

Balance at December 31, 2017

 

 

3,555

 

 

$

19.56

 

 

 

 

 

 

 

 

 

Options granted

 

 

2,503

 

 

 

16.30

 

 

 

 

 

 

 

 

 

Options exercised

 

 

(42

)

 

 

11.80

 

 

 

 

 

 

 

 

 

Options cancelled:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Options forfeited (unvested)

 

 

(178

)

 

 

14.29

 

 

 

 

 

 

 

 

 

Options expired (vested)

 

 

(88

)

 

 

29.58

 

 

 

 

 

 

 

 

 

Balance at December 31, 2018

 

 

5,750

 

 

$

18.20

 

 

 

5.47

 

 

$

651

 

Vested and expected to vest at December 31, 2018

 

 

5,534

 

 

$

18.28

 

 

 

5.44

 

 

$

644

 

Exercisable at December 31, 2018

 

 

2,975

 

 

$

19.90

 

 

 

4.87

 

 

$

466

 

 

Summary of Non-vested Restricted Stock Units Activity

Our non-vested stock awards are comprised of restricted stock units granted with performance and time-based vesting criteria. A summary of the status of non-vested restricted stock units as of December 31, 2018, and activities during 2018 are summarized as follows:  

 

 

Number of Shares

(In thousands)

 

 

Weighted-Average

Grant-Date Fair Value

 

Non-vested as of December 31, 2017

 

2,443

 

 

$

6.01

 

Granted

 

458

 

 

 

15.98

 

Vested

 

(1,219

)

 

 

5.86

 

Forfeited

 

(88

)

 

 

9.07

 

Non-vested as of December 31, 2018

 

1,594

 

 

$

8.82

 

 

Fair Value-Based Measurements and Weighted-Average Assumptions The fair value of each option is estimated on the date of grant using the Black-Scholes option valuation model and the following weighted-average assumptions:

 

 

Stock Options

 

 

Employee Stock Purchase Plan

 

 

 

Year Ended December 31,

 

 

Year Ended December 31,

 

 

 

2018

 

 

2017

 

 

2016

 

 

2018

 

 

2017

 

 

2016

 

Weighted-average fair value

 

$

10.75

 

 

$

8.27

 

 

$

9.54

 

 

$

8.30

 

 

$

3.05

 

 

$

7.86

 

Risk-free interest rate

 

 

2.5

%

 

 

1.9

%

 

 

1.4

%

 

 

2.4

%

 

 

1.0

%

 

 

0.6

%

Expected life (in years)

 

 

4.2

 

 

 

4.5

 

 

 

4.9

 

 

 

1.3

 

 

 

1.2

 

 

 

1.2

 

Expected Volatility

 

 

0.8

 

 

 

0.9

 

 

 

0.7

 

 

 

1.1

 

 

 

1.0

 

 

 

0.6

 

Stock-Based Compensation Expense

We recognized the following amounts of stock-based compensation expense (in thousands):

 

 

 

Year Ended December 31,

 

 

 

2018

 

 

2017

 

 

2016

 

Employees and directors stock-based compensation expense

 

$

23,478

 

 

$

14,917

 

 

$

14,126

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Year Ended December 31,

 

 

 

2018

 

 

2017

 

 

2016

 

Research and development

 

$

9,604

 

 

$

7,827

 

 

$

6,742

 

Selling, general and administrative

 

 

11,761

 

 

 

7,090

 

 

 

7,384

 

Cost of sales - product

 

 

1,354

 

 

 

-

 

 

 

-

 

Inventory

 

 

759

 

 

 

-

 

 

 

-

 

Total

 

$

23,478

 

 

$

14,917

 

 

$

14,126