POST EMPLOYMENT BENEFITS - Plan assets distribution (Details)	Sep. 30, 2024	Sep. 30, 2023
Plan assets distribution
Plan assets distribution (in percent)	100.00%	100.00%
Cash
Plan assets distribution
Plan assets distribution (in percent)	2.69%	3.31%
Equity securities
Plan assets distribution
Plan assets distribution (in percent)	3.47%	2.35%
Debt securities
Plan assets distribution
Plan assets distribution (in percent)	91.05%	91.23%
Real estate mutual fund
Plan assets distribution
Plan assets distribution (in percent)	1.10%	1.20%
Other
Plan assets distribution
Plan assets distribution (in percent)	1.69%	1.91%