Quarterly report pursuant to Section 13 or 15(d)

Equity Incentive Plan (Details)

v3.7.0.1
Equity Incentive Plan (Details) - Second Restated 2009 Equity Incentive Plan [Member] - $ / shares
 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
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) 1,343,689 1,759,737
Weighted average grant date fair value of restricted common shares granted during period under equity incentive plan (in usd per share) $ 8.80 $ 7.38
Award vesting period of restricted common shares granted during period under equity incentive plan 3 years  
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) 69,117 81,739
Weighted average grant date fair value of restricted common shares granted during period under equity incentive plan (in usd per share) $ 9.91 $ 8.43
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) 1,274,572 1,677,998
Weighted average grant date fair value of restricted common shares granted during period under equity incentive plan (in usd per share) $ 8.74 $ 7.33
Common stock share price (in usd per share) $ 9.91