EARNINGS PER SHARE - Company's Class A and Class B Common and Treasury Shares (Details) - shares	Mar. 31, 2026	Sep. 30, 2025
Class A Common Stock
Class of Stock [Line Items]
Authorized Shares (in shares)	128,000,000	128,000,000
Issued Shares (in shares)	42,281,920	42,281,920
Outstanding Shares (in shares)	24,776,629	26,169,944
Treasury Shares (in shares)	17,505,291	16,111,976
Class B Common Stock
Class of Stock [Line Items]
Authorized Shares (in shares)	69,120,000	69,120,000
Issued Shares (in shares)	34,560,000	34,560,000
Outstanding Shares (in shares)	21,391,398	21,331,127
Treasury Shares (in shares)	13,168,602	13,228,873