Annual report pursuant to Section 13 and 15(d)

Compensation and Other Benefit Plans - Stock Option Plans (Details)

v3.20.1
Compensation and Other Benefit Plans - Stock Option Plans (Details) - shares
1 Months Ended 12 Months Ended
May 31, 2019
May 31, 2017
May 31, 2016
Dec. 31, 2019
Dec. 31, 2018
Share-based compensation          
Number of options outstanding       1,839,623 1,624,746
2010 Plan          
Share-based compensation          
Increase in aggregate number of shares authorized for issuance 450,000   170,000    
Shares authorized for issuance 3,029,062   1,108,560    
2010 Plan | Minimum | Terminated employee          
Share-based compensation          
Expiration period       3 months  
2010 Plan | Maximum          
Share-based compensation          
Expiration period       10 years  
2010 Plan | Maximum | Terminated employee          
Share-based compensation          
Expiration period       6 months  
2010 Plan | Options and Stock Appreciation Rights          
Share-based compensation          
Maximum shares per employee   2,000,000      
2010 Plan | Other Types of Stock Awards          
Share-based compensation          
Maximum shares per employee   2,000,000      
2010 Plan | Stock Options          
Share-based compensation          
Increase in aggregate number of shares authorized for issuance 450,000        
Shares authorized for issuance 3,029,062        
Shares available for grant       525,020  
2010 Plan | Common Stock          
Share-based compensation          
Increase in aggregate number of shares authorized for issuance   1,470,502      
Shares authorized for issuance   2,579,062      
2010 Plan | Common Stock | Stock Options          
Share-based compensation          
Increase in aggregate number of shares authorized for issuance   2,004,087      
Shares authorized for issuance   2,579,062