Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation (Details)

v3.19.1
Stock Based Compensation (Details) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock based compensation expense $ 2.8 $ 1.5
Restricted Share Awards    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Fair value of share grants vested $ 1.3 $ 0.7
Total unvested restricted share awards (in shares) 447,908  
Weighted average grant date fair value (in dollars per share) $ 28.00  
Total compensation costs, non-vested restricted share awards $ 10.3  
Total compensation cost not yet recognized, period for recognition (in months) 28 months  
Washington Real Estate Investment Trust 2016 Omnibus Incentive Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock based plan, aggregate number of shares authorized (in shares) 2,400,000.0  
Stock based plan, period in effect (in years) 10 years