XML 46 R31.htm IDEA: XBRL DOCUMENT v3.20.4
Stock-Based Compensation (Tables)
 12 Months Ended
Dec. 31, 2020
Share-based Payment Arrangement [Abstract]  
Stock-Based Compensation Expense We recognize total stock-based compensation expense in our Consolidated Statements of Operations as follows (in thousands):
Year Ended December 31,
202020192018
Cost of goods sold
$2,825 $4,294 $4,629 
Research and development
57,116 63,224 56,193 
General and administrative
33,295 32,277 27,279 
Impairment of assets and other costs for terminated program1,025 — — 
Total stock-based compensation$94,261 $99,795 $88,101 
Black-Scholes Option-Pricing Model Assumptions Used to Calculate Fair Value of Employee Stock Options The following table lists the Black-Scholes option-pricing model assumptions used to calculate the fair value of employee and director stock options, as well as the resulting grant-date fair value:
Year Ended December 31,
202020192018
Average risk-free interest rate0.4 %1.8 %2.8 %
Dividend yield0.0 %0.0 %0.0 %
Average volatility factor64.1 %62.2 %61.0 %
Weighted-average expected life5.6 years5.6 years5.1 years
Weighted-average grant-date fair value of options granted$10.70$12.25$29.86
Stock Option Activity Under Equity Incentive Plans The table below presents a summary of stock option activity under our equity incentive plans (in thousands, except for price per share and contractual life information):
Number
of
Shares
Weighted-
Average
Exercise
Price
per Share
Weighted-
Average
Remaining
Contractual
Life
(in Years)
Aggregate
Intrinsic
Value(1)
Outstanding at December 31, 201914,885 $25.23 
Options granted
1,654 19.15 
Options exercised
(1,669)11.69 
Options forfeited & canceled
(1,233)45.70 
Outstanding at December 31, 202013,637 $24.30 3.96$23,478 
Exercisable at December 31, 20209,523 22.99 2.71$23,468 
_______________________________________________________________
(1)Aggregate intrinsic value represents the difference between the exercise price of the option and the closing market price of our common stock on December 31, 2020.
Restricted Stock Unit Award Activity A summary of RSU award activity is as follows (in thousands except for per share amounts):
Units IssuedWeighted-
Average
Grant
Date Fair
Value
Balance at December 31, 20194,935 $30.85 
Granted4,686 19.24 
Vested and released(1,661)34.83 
Forfeited and canceled(866)29.66 
Balance at December 31, 20207,094 $22.46