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Stock-based Compensation - Summary of the Status of the Trust's Non-Vested Restricted Common Shares (Details) - 2013 Plan - Restricted common shares
6 Months Ended
Jun. 30, 2017
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]  
Non-vested at the beginning of the period (in shares) | shares 296,785
Granted (in shares) | shares 143,593
Vested (in shares) | shares (239,587)
Forfeited (in shares) | shares (550)
Non-vested at the end of the period (in shares) | shares 200,241
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]  
Non-vested at beginning of period (in dollars per share) | $ / shares $ 16.16
Granted (in dollars per share) | $ / shares 19.74
Vested (in dollars per share) | $ / shares 16.11
Forfeited (in shares) | $ / shares 18.78
Non-vested at end of period (in dollars per share) | $ / shares $ 18.77