XML 94 R76.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock Based Compensation - Additional Information (Detail) - USD ($)
1 Months Ended 12 Months Ended
Jul. 31, 2018
Dec. 31, 2017
Jun. 30, 2017
Mar. 31, 2017
Sep. 30, 2016
Jun. 30, 2016
Feb. 29, 2016
Oct. 31, 2015
Jun. 30, 2015
Jun. 30, 2013
Nov. 30, 2012
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Jun. 30, 2018
Dec. 31, 2015
Sep. 30, 2014
Jun. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Term of award                       10 years            
Share based compensation granted under plan vest period                       4 years            
Weighted-average grant date fair value per share of stock-based awards, granted to employees                       $ 44.66 $ 14.78 $ 12.46        
Stock option grants with performance conditions                       2,152,439 4,805,722 [1] 1,285,051        
Stock-based compensation expense                       $ 50,127,000 $ 30,465,000 $ 29,962,000        
Former Chief Executive Officer [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Stock-based compensation expense                         2,100,000          
Stock Options [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Share based compensation granted under plan vest period             4 years     4 years                
Stock option grants with performance conditions             300,000     400,000                
Forfeited awards percentage                           20.00%        
Stock-based compensation expense                       37,671,000 23,416,000 $ 26,320,000        
Stock Options [Member] | EXONDYS 51 [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Vesting percentage                           80.00%        
Stock Options [Member] | Performance Grants Vested Immediately [Member] | EXONDYS 51 [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Vesting percentage             50.00%                      
Stock Options [Member] | Vesting Subject to the Remaining Service Conditions [Member] | EXONDYS 51 [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Vesting percentage             50.00%                      
Stock Options with Performance-based Conditions [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Stock-based compensation expense                       200,000 $ 900,000 $ 5,000,000        
Service-Vesting Conditions [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Stock based compensation expense not yet recognized                       73,000,000            
Stock Options with Service-and Performance-Based Conditions [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Stock based compensation expense not yet recognized                       200,000            
Market Based Conditions [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Stock based compensation expense not yet recognized                       $ 31,000,000            
Restricted Stock Awards (RSAs) [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Grants, Restricted stock units and awards                       27,590 341,500 117,553        
Grant date fair value, restricted stock units and awards                       $ 98.57 $ 34.58 $ 41.22        
Outstanding, Restricted stock units and awards   411,781                   252,321 411,781 153,170   161,320    
Restricted Stock Awards (RSAs) [Member] | Minimum [Member] | Executives [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Stock-based compensation expense                         $ 0          
Grants, Restricted stock units and awards         71,925                          
Share-based compensation award, expiration date   Jun. 30, 2018                                
Grant date fair value, restricted stock units and awards         $ 48.94                          
Restricted Stock Awards (RSAs) [Member] | Maximum [Member] | Executives [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Stock-based compensation expense                       $ 3,300,000            
Grants, Restricted stock units and awards         89,906                          
Share-based compensation award, expiration date   Jan. 01, 2019                                
Grant date fair value, restricted stock units and awards         $ 54.29                          
Restricted Stock Units (RSUs) [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Grants, Restricted stock units and awards                       230,736 181,029          
Grant date fair value, restricted stock units and awards                       $ 87.95 $ 33.03          
Outstanding, Restricted stock units and awards   66,552                   251,298 66,552          
Restricted Stock Units (RSUs) [Member] | Executives [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Stock-based compensation expense                       $ 2,900,000 $ 200,000          
Grants, Restricted stock units and awards       156,029                            
Restricted Stock Units (RSUs) [Member] | Maximum [Member] | Executives [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Stock-based compensation related to grants                       $ 700,000            
Stock Appreciation Rights [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Vested, Restricted stock units and awards   100,000                   100,000 100,000 100,000        
Outstanding, Restricted stock units and awards   100,000                   100,000 100,000 100,000   100,000    
Exercise price of SARs                     $ 23.85              
2011 Equity Incentive Plan [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Common stock remain available for future grant                       0            
Number of shares approved under the plan                                   13,000,000
Number of additional shares approved under the plan           1,300,000     1,700,000                  
2013 Employee Stock Purchase Plan [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Common stock remain available for future grant                       200,000            
Number of shares approved under the plan           300,000       300,000                
Term of award                       24 months            
Percentage of closing price of common stock                       85.00%            
2013 Employee Stock Purchase Plan [Member] | Minimum [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Share-based compensation award, expiration date                       Feb. 28, 2018            
2013 Employee Stock Purchase Plan [Member] | Maximum [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Share-based compensation award, expiration date                       Aug. 31, 2019            
2014 Employment Commencement Incentive Plan (2014 Plan) [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Common stock remain available for future grant                       900,000            
Number of shares approved under the plan                                 600,000  
Number of additional shares approved under the plan 1,200,000   3,800,000         1,000,000                    
2018 Equity Incentive Plan [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                    
Common stock remain available for future grant                       4,400,000            
Number of shares approved under the plan                             2,900,000      
[1] In June 2017, the Company granted its new CEO 3,300,000 options with service and market conditions. These options have a five-year cliff vesting schedule. The fair value of $13.48 for these options was determined by a lattice model with Monte Carlo simulations. The remaining are service-based options which have a four-year vesting schedule with 25% vesting on the first anniversary and 1/48 monthly thereafter.