Annual report pursuant to Section 13 and 15(d)

Equity Incentive Plan (Details)

v3.19.3.a.u2
Equity Incentive Plan (Details) - $ / shares
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
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) 515,282 996,924  
Weighted average grant date fair value of restricted common shares granted during period under equity incentive plan (in usd per share) $ 14.28 $ 14.96  
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) 60,108 55,553 34,559
Weighted average grant date fair value of restricted common shares granted during period under equity incentive plan (in usd per share) $ 13.35 $ 15.48 $ 19.82
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) 455,174 941,371 637,286
Weighted average grant date fair value of restricted common shares granted during period under equity incentive plan (in usd per share) $ 14.40 $ 15.12 $ 17.48
Award vesting period of restricted common shares granted during period under equity incentive plan 3 years