XML 58 R58.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stock Based Compensation (Narrative) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation expense and directors' fees related to stock awards $ 15.1 $ 9.7 $ 9.5
Compensation expense, non-vested awards $ 13.6 $ 8.6 $ 7.7
Number of shares issued to employees, directors and officers (in shares) 292,675    
Nonvested awards, total compensation cost not yet recognized $ 3.5    
Weighted Average      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Nonvested awards, total compensation cost not yet recognized, period for recognition 1 year    
Stock Awards | Independent directors      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting period 1 year