Quarterly report pursuant to Section 13 or 15(d)

Pension and Other Postretirement Benefit Plans (Details)

v3.4.0.3
Pension and Other Postretirement Benefit Plans (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Mar. 31, 2016
Mar. 31, 2015
Pension [Member]        
Net periodic benefit cost [Abstract]        
Service cost $ 1,813 $ 1,655 $ 3,626 $ 3,310
Interest cost 2,406 2,145 4,812 4,290
Expected return on plan assets (2,407) (2,470) (4,814) (4,940)
Amortization [Abstract]        
Prior service cost (46) (45) (92) (90)
Net actuarial loss 1,866 1,564 3,732 3,128
Net benefit cost 3,632 2,849 7,264 5,698
Other Postretirement Plans [Member]        
Net periodic benefit cost [Abstract]        
Service cost 101 114 202 228
Interest cost 211 221 422 442
Expected return on plan assets 0 0 0 0
Amortization [Abstract]        
Prior service cost (49) (49) (98) (98)
Net actuarial loss 0 0 0 0
Net benefit cost $ 263 $ 286 526 $ 572
Benefit plan contributions [Abstract]        
Other postretirement plan     672  
Additional contributions expected in fiscal 2016     336  
Supplemental Retirement Plan [Member]        
Benefit plan contributions [Abstract]        
Supplemental retirement plan     362  
Additional contributions expected in fiscal 2016     $ 387