Annual report pursuant to Section 13 and 15(d)

PENSION AND OTHER POSTRETIREMENT PLANS - Weighted Average Asset Allocation and Target Allocation (Details)

v3.21.2
PENSION AND OTHER POSTRETIREMENT PLANS - Weighted Average Asset Allocation and Target Allocation (Details) - USD ($)
$ in Thousands
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2019
Defined Benefit Plan, Actual Plan Asset Allocations [Abstract]      
Fair value of plan assets $ 208,344 $ 168,134  
Pension      
Defined Benefit Plan, Actual Plan Asset Allocations [Abstract]      
Fair value of plan assets $ 208,344 168,134 $ 155,313
Defined Benefit Plan, Plan Assets, Allocations [Abstract]      
Target allocation of plan assets (as a percent) 100.00%    
Equity securities | Pension      
Defined Benefit Plan, Actual Plan Asset Allocations [Abstract]      
Fair value of plan assets $ 4,075 118,677  
Defined Benefit Plan, Plan Assets, Allocations [Abstract]      
Target allocation of plan assets (as a percent) 0.00%    
Fixed income, cash and cash equivalents | Pension      
Defined Benefit Plan, Actual Plan Asset Allocations [Abstract]      
Fair value of plan assets $ 189,958 34,184  
Defined Benefit Plan, Plan Assets, Allocations [Abstract]      
Target allocation of plan assets (as a percent) 100.00%    
Other investments | Pension      
Defined Benefit Plan, Actual Plan Asset Allocations [Abstract]      
Fair value of plan assets $ 14,311 $ 15,273  
Defined Benefit Plan, Plan Assets, Allocations [Abstract]      
Target allocation of plan assets (as a percent) 0.00%