Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation and Other Compensation Matters (Details 5)

v3.8.0.1
Share-Based Compensation and Other Compensation Matters (Details 5) - Deferred Share Award [Member] - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of Deferred Share Awards Granted (in shares or units) 10,032 24,944 24,056
Aggregate Grant Date Fair Value $ 326 $ 671 $ 642
Grant Date Fair Value Per Share (in dollars per share) $ 32.47 $ 26.89 $ 26.70
Number of common shares issued (in shares) 15,590 12,028 15,485
Grant date fair value (in dollars per share) $ 26.89 $ 26.70 $ 26.77
Aggregate intrinsic value $ 508 $ 322 $ 413