Quarterly report pursuant to Section 13 or 15(d)

Employee Retirement Plans (Details)

v3.5.0.2
Employee Retirement Plans (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Pension plan        
Components of net periodic cost:        
Service cost $ 80 $ 64 $ 241 $ 192
Interest cost 410 372 1,229 1,116
Expected return on plan assets (456) (407) (1,368) (1,221)
Amortization of net (gain) loss 181 255 543 765
Net periodic cost 215 284 645 852
Employer contributions during the period     711 572
Pension plan | Minimum        
Components of net periodic cost:        
Estimated total required contributions 967   967  
Other postretirement benefit cost        
Components of net periodic cost:        
Service cost 52 57 158 171
Interest cost 69 64 209 192
Amortization of net (gain) loss (31) (17) (95) (51)
Net periodic cost $ 90 $ 104 $ 272 $ 312