XML 89 R77.htm IDEA: XBRL DOCUMENT v3.7.0.1
Equity Incentive Programs (Deferred Stock Unit Activity) (Details) - Deferred Stock Units (DSUs) [Member] - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Units    
Outstanding at beginning of period (in shares) 249,739  
Granted (in shares) 34,656  
Dividend equivalents granted (in shares) 3,373  
Settled (in shares) 0  
Forfeited (in shares) 0  
Outstanding at end of period (in shares) 287,768  
Weighted-Average Grant Date Fair Value Per Share    
Outstanding at beginning of period (in dollars per share) $ 16.98  
Granted (in dollars per share) 26.86  
Dividend equivalents granted (in dollars per share) 25.05  
Settled (in dollars per share) 0.00  
Forfeited (in dollars per share) 0.00  
Outstanding at end of period (in dollars per share) $ 18.27  
Number of DSU to class A common share conversion (in shares) 1  
Compensation expense $ 0.9 $ 0.8