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Stock-Based Compensation (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Additional disclosures [Abstract]      
Stock-based compensation expense $ 4,210 $ 3,936 $ 3,644
Number of shares available for future grant (in shares) 988,494    
Stock Options [Member]      
Share-based compensation [Abstract]      
Stock awards termination period 10 years    
Stock options [Roll Forward]      
Outstanding, beginning of period (in shares) 66,900    
Exercised (in shares) (32,505)    
Expired (in shares) (1,250)    
Outstanding, end of period (in shares) 33,145 66,900  
Exercisable, end of period (in shares) 33,145    
Stock options, weighted average exercise price [Abstract]      
Outstanding, beginning of period (in dollars per share) $ 23.07    
Exercised (in dollars per share) 22.31    
Expired (in dollars per share) 25.38    
Outstanding, end of period (in dollars per share) 23.73 $ 23.07  
Exercisable, end of period (in dollars per share) $ 23.73    
Additional disclosures [Abstract]      
Weighted average remaining contractual term, outstanding, end of period 1 year 10 months 9 days    
Weighted average remaining contractual term, exercisable, end of period 1 year 10 months 9 days    
Aggregate intrinsic value, outstanding, end of period $ 558,066    
Aggregate intrinsic value, exercisable, end of period 558,066    
Stock-based compensation expense 1 $ 11 18
Proceeds from stock options exercised 725 999 3,083
Tax benefits related to stock options exercised 123 173 650
Intrinsic value of stock options exercised 490 692 1,699
Fair value of shares vested during the year 13 16 329
Restricted Stock [Member]      
Additional disclosures [Abstract]      
Stock-based compensation expense $ 4,200 $ 3,900 3,500
Restricted Stock [Member] | Employees [Member] | Minimum [Member]      
Share-based compensation [Abstract]      
Stock awards vesting period 3 years    
Restricted Stock [Member] | Employees [Member] | Maximum [Member]      
Share-based compensation [Abstract]      
Stock awards vesting period 5 years    
Restricted Stock [Member] | Non-employee Directors [Member]      
Share-based compensation [Abstract]      
Stock awards vesting period 3 years    
Restricted Stock Units (RSUs) [Member]      
Restricted stock and restricted stock units [Roll Forward]      
Unvested, beginning of period (in shares) 546,054    
Forfeited (in shares) (10,886)    
Vested (in shares) (121,774)    
Granted (in shares) 142,046    
Unvested, end of period (in shares) 555,440 546,054  
Restricted stock and restricted stock units, weighted average grant date fair value [Abstract]      
Unvested, beginning of period (in dollars per share) $ 28.39    
Forfeited (in dollars per share) 31.06    
Vested (in dollars per share) 25.66    
Granted (in dollars per share) 33.04    
Unvested, end of period (in dollars per share) $ 30.11 $ 28.39  
Restricted Stock Awards and Stock Units [Member]      
Additional disclosures [Abstract]      
Tax benefit on restricted stock awards $ 1,100 $ 1,200 $ 2,500
Unrecognized compensation cost $ 5,500    
Unrecognized compensation cost, weighted average period of recognition 1 year 9 months 18 days