Quarterly report pursuant to Section 13 or 15(d)

Pension and Other Postretirement Benefit Plans (Details)

v3.8.0.1
Pension and Other Postretirement Benefit Plans (Details) - USD ($)
$ in Thousands
 3 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Pension    
Net periodic benefit cost [Abstract]    
Service cost $ 2,039 $ 2,138
Interest cost 2,049 1,841
Expected return on plan assets (2,534) (2,312)
Amortization:    
Prior service cost (35) (45)
Net actuarial loss 1,752 2,509
Net benefit cost 3,271 4,131
Supplemental retirement plan    
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]    
Pension 184  
Other Postretirement 0  
Additional contributions expected in fiscal 2018: 582  
Other Postretirement    
Net periodic benefit cost [Abstract]    
Service cost 84 98
Interest cost 158 157
Expected return on plan assets 0 0
Amortization:    
Prior service cost (49) (49)
Net actuarial loss 0 0
Net benefit cost 193 $ 206
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]    
Pension 0  
Other Postretirement 437  
Additional contributions expected in fiscal 2018: $ 607