Annual report pursuant to Section 13 and 15(d)

Retirement and Long-Term Incentive Plans - Narrative (Details)

v3.6.0.2
Retirement and Long-Term Incentive Plans - Narrative (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Employer discretionary contribution $ 670 $ 2,300 $ 2,600  
Available shares for future issuance (in shares) 1,123,482      
Total unrecognized compensation costs $ 2,600      
Recognition of compensation cost, weighted average period 1 year 8 months 12 days      
Total fair value of shares vested $ 1,200      
Share-based compensation cost charged against income 3,125 2,707 1,139  
Total income tax benefit under share-base compensation 0 0 49  
Incentive Plans        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation cost charged against income $ 2,100 $ 2,700 $ 1,100  
Employee Stock Option        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares authorized (in shares) 1,000,000      
Employee Stock Option | Long Term Incentive Plan 2002        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares authorized (in shares) 500,000      
Employee Stock Option | Long Term Incentive Plan 2011        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares authorized (in shares) 500,000      
Employee Stock Option | Long Term Incentive Plan 2015        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares authorized (in shares) 1,000,000      
Non Performance Based        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Restricted stock vesting period, minimum 3 years      
Restricted Stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of share awards 370,565 262,964.000 107,840 178,950
Restricted Stock | Non-employee directors        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Restricted stock vesting period 6 months      
Performance Shares        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of share awards     0 0
Performance based share compensation expense $ 1,300 $ 1,100 $ 0  
Fair value of performance based shares granted $ 1,600 $ 2,700    
Maximum | Employee Stock Option        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options available for grant to an individual (in shares) 400,000      
Maximum | Employee Stock Option | Long Term Incentive Plan 2002        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options available for grant to an individual (in shares) 200,000      
Maximum | Employee Stock Option | Long Term Incentive Plan 2011        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options available for grant to an individual (in shares) 200,000      
Maximum | Employee Stock Option | Long Term Incentive Plan 2015        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options available for grant to an individual (in shares) 200,000      
Options available for grant to an outside director (in shares) 25,000      
2015 Awards        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Performance period awards are earned   2 years    
2016 Awards        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Performance period awards are earned 3 years