STOCK INCENTIVE PLAN - Schedule of Nonvested Performance Shares (Details) - $ / shares shares in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Shares
Nonvested, Added by dividends (in shares)	4	1
Weighted-average grant-date fair value
Nonvested, Added by dividends (in dollars per share)	$ 118.30	$ 126.08
Performance Shares
Shares
Nonvested, beginning balance (in shares)	165	273	313
Nonvested, granted (in shares)	114	67	69
Nonvested, vested (in shares)	(60)	(269)	(190)
Nonvested, Adjustment for achieved performance (in shares)	24	117	83
Nonvested, forfeited (in shares)	(17)	(24)	(1)
Nonvested, ending balance (in shares)	230	165	273
Weighted-average grant-date fair value
Nonvested, beginning of year (in dollars per share)	$ 126.17	$ 67.02	$ 48.19
Nonvested, granted (in dollars per share)	105.02	151.18	110.71
Nonvested, vested (in dollars per share)	109.22	31.39	39.94
Nonvested, Adjustment for achieved performance (in dollars per share)	105.94	31.02	39.31
Nonvested, forfeited (in dollars per share)	118.00	125.08	31.67
Nonvested, ending of year (in dollars per share)	$ 118.44	$ 126.17	$ 67.02