RETIREMENT PLANS - ASSET CATERGORY ALLOCATION (Details)	Sep. 30, 2021	Sep. 30, 2020
Cash and other
Entity's year-end target allocation, by asset category, and the actual asset allocations
Actual asset allocation	0.00%	0.00%
Fixed income securities
Entity's year-end target allocation, by asset category, and the actual asset allocations
Actual asset allocation	31.00%	52.00%
Equity securities
Entity's year-end target allocation, by asset category, and the actual asset allocations
Actual asset allocation	69.00%	48.00%
Minimum | Cash and other
Entity's year-end target allocation, by asset category, and the actual asset allocations
Target allocation	0.00%
Minimum | Fixed income securities
Entity's year-end target allocation, by asset category, and the actual asset allocations
Target allocation	15.00%
Minimum | Equity securities
Entity's year-end target allocation, by asset category, and the actual asset allocations
Target allocation	45.00%
Maximum | Cash and other
Entity's year-end target allocation, by asset category, and the actual asset allocations
Target allocation	15.00%
Maximum | Fixed income securities
Entity's year-end target allocation, by asset category, and the actual asset allocations
Target allocation	40.00%
Maximum | Equity securities
Entity's year-end target allocation, by asset category, and the actual asset allocations
Target allocation	75.00%