XML 112 R97.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock Plans and Stock Based Compensation - Activity Related to Stock Options and SARs Under All Plans (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Number of Shares/Rights      
Granted (in shares) 65,785 59,333 73,716
Outstanding, ending balance (in shares) 225,375    
Exercisable, ending balance (in shares) 139,483    
Weighted Average Exercise Price      
Outstanding, ending balance (in dollars per share) $ 48.02    
Exercisable, ending balance (in dollars per share) $ 44.06    
Weighted Average Remaining Contractual Term      
Outstanding (in years) 4 years 6 months 23 days    
Stock Options And Stock Appreciation Rights      
Number of Shares/Rights      
Outstanding, beginning balance (in shares) 269,506    
Granted (in shares) 0    
Exercised (in shares) (33,745)    
Forfeited (in shares) (10,386)    
Outstanding, ending balance (in shares) 225,375 269,506  
Exercisable, ending balance (in shares) 139,483    
Weighted Average Exercise Price      
Outstanding, beginning balance (in dollars per share) $ 47.34    
Granted (in dollars per share) 0.00    
Exercised (in dollars per share) 41.22    
Forfeited (in dollars per share) 52.53    
Outstanding, ending balance (in dollars per share) 48.02 $ 47.34  
Exercisable, ending balance (in dollars per share) $ 44.06    
Weighted Average Remaining Contractual Term      
Outstanding (in years) 4 years 6 months 22 days    
Exercisable (in years) 3 years 6 months 22 days    
Aggregate Intrinsic Value      
Outstanding $ 6,118,933    
Exercisable $ 4,326,073