Quarterly report pursuant to Section 13 or 15(d)

Equity Incentive Plan (Details)

v3.19.2
Equity Incentive Plan (Details) - $ / shares
 6 Months Ended
Jun. 30, 2019
Jun. 30, 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) 515,282 985,616
Weighted average grant date fair value of restricted common shares granted during period under equity incentive plan (in usd per share) $ 14.28 $ 15.14
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 44,245
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
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
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
Award vesting period of restricted common shares granted during period under equity incentive plan 3 years