Annual report pursuant to Section 13 and 15(d)

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

v3.20.2
PENSION AND OTHER POSTRETIREMENT PLANS - Net Periodic Pension and Other Postretirement Benefit Cost (Details) - USD ($)
$ in Thousands
 12 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2018
Pension      
Defined Benefit Plan Disclosure [Line Items]      
Service cost $ 8,679 $ 7,998 $ 8,159
Interest cost 7,735 9,202 8,210
Expected return on plan assets * (10,214) (10,304) (10,136)
Prior service cost (186) (186) (138)
Net actuarial loss * 9,767 4,245 7,018
Net benefit cost 15,781 10,955 13,113
Other Postretirement      
Defined Benefit Plan Disclosure [Line Items]      
Service cost 227 244 335
Interest cost 501 718 631
Expected return on plan assets * 0 0 0
Prior service cost (464) (195) (195)
Net actuarial loss * 0 (59) 0
Net benefit cost $ 264 $ 708 $ 771