Annual report pursuant to Section 13 and 15(d)

Equity Incentive Plan (Details)

v3.20.4
Equity Incentive Plan (Details) - $ / shares
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of restricted common shares reserved for issuance under equity incentive plan (in shares) 6,500,000    
Number of restricted common shares granted during period under equity incentive plan (in shares) 855,712 515,282  
Weighted average grant date fair value of restricted common shares granted during period under equity incentive plan (in usd per share) $ 13.16 $ 14.28  
Director [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of restricted common shares granted during period under equity incentive plan (in shares) 168,942 60,108 55,553
Weighted average grant date fair value of restricted common shares granted during period under equity incentive plan (in usd per share) $ 4.75 $ 13.35 $ 15.48
Award vesting period of restricted common shares granted during period under equity incentive plan 1 year    
Key Employees [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of restricted common shares granted during period under equity incentive plan (in shares) 686,770 455,174 941,371
Weighted average grant date fair value of restricted common shares granted during period under equity incentive plan (in usd per share) $ 15.23 $ 14.40 $ 15.12
Award vesting period of restricted common shares granted during period under equity incentive plan 3 years