XML 39 R29.htm IDEA: XBRL DOCUMENT v3.20.2
Stock-Based Compensation (Tables)
 6 Months Ended
Jun. 30, 2020
Share-based Payment Arrangement [Abstract]  
Summary of Option Activity Plan
A summary of option activity under the Plans for the six months ended June 30, 2020 follows:
 
2006 and 2016 Plans
(in thousands, except for share and per share amounts)
Number of
Shares		Weighted Average
Exercise Price at
Grant Date		Weighted Average
Remaining Term
(Years)		Aggregate
Intrinsic
Value
Outstanding at December 31, 20194,495,145  $12.21  5.58$22,148  
Granted537,500  11.34  
Forfeited(225,000) 18.83  
Expired(545,104) 14.29  
Exercised(554,844) 7.35  2,113  
Outstanding at June 30, 20203,707,697  12.10  5.905,415  
Exercisable at June 30, 20202,562,003  10.95  4.515,317  
Vested and expected to vest at June 30, 20203,518,867  12.03  5.715,395  
Summary of RSU Activity for 2006 Plan and 2016 Plan
A summary of RSU activity under the Plans for the six months ended June 30, 2020 follows:
2006 and 2016 Plans
Number of
Shares
Underlying RSUs
Weighted
Average
Grant Date Fair Value
Unvested at December 31, 20191,649,285  $18.04  
Granted786,818  11.28  
Forfeited(174,577) 18.19  
Vested(523,880) 16.65  
Unvested at June 30, 20201,737,646  15.39  
Stock-Based Compensation Expense
Stock-based compensation expense recognized for the three and six months ended June 30, 2020 and 2019 was comprised of the following:
 
 Three Months EndedSix Months Ended
(in thousands)June 30,
2020		June 30,
2019		June 30,
2020		June 30,
2019
Research and development$900  $756  $2,011  $1,484  
Selling, general and administrative2,169  2,345  5,002  4,899  
Total stock-based compensation expense$3,069  $3,101  $7,013  $6,383  
Black-Scholes-Merton Option Pricing Model for Employee and Director Stock Options Granted Assumptions used in the Black-Scholes-Merton option pricing model for employee and director stock options granted during the six months ended June 30, 2020 and 2019 were as follows:
 
 Six Months Ended
June 30, 2020June 30, 2019
Expected dividend yield0 %0 %
Weighted average expected volatility52 %59 %
Weighted average expected term (years)6.095.93
Weighted average risk-free rate1.28 %2.48 %