Annual report pursuant to Section 13 and 15(d)

PENSION AND OTHER POSTRETIREMENT PLANS - Net Periodic Pension and Other Postretirement Benefit Cost (Details)

v3.21.2
PENSION AND OTHER POSTRETIREMENT PLANS - Net Periodic Pension and Other Postretirement Benefit Cost (Details) - USD ($)
$ in Thousands
 12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2019
Pension      
Defined Benefit Plan Disclosure [Line Items]      
Service cost $ 7,919 $ 8,679 $ 7,998
Interest cost 6,145 7,735 9,202
Expected return on plan assets (10,809) (10,214) (10,304)
Prior service cost (127) (186) (186)
Net actuarial loss 9,769 9,767 4,245
Curtailment gain (220) 0 0
Special termination benefits 315 0 0
Prior-service cost write-off 261 0 0
Net benefit cost 13,253 15,781 10,955
Other Postretirement      
Defined Benefit Plan Disclosure [Line Items]      
Service cost 201 227 244
Interest cost 376 501 718
Expected return on plan assets 0 0 0
Prior service cost (364) (464) (195)
Net actuarial loss 0 0 (59)
Curtailment gain 0 0 0
Special termination benefits 0 0 0
Prior-service cost write-off 0 0 0
Net benefit cost $ 213 $ 264 $ 708