SCHEDULE I - CONDENSED FINANCIAL INFORMATION - Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Assets
Total Assets	$ 2,851,922	$ 3,021,403	$ 2,935,009
Liabilities and Equity
Total Liabilities	1,453,581	1,481,503
Equity:
Common stock, $0.01 par value, 1,000,000,000 shares authorized, 33,665,258 and 34,859,033 shares issued and outstanding, respectively	338	350
Additional paid-in capital	526,600	509,254
Retained earnings	889,391	1,049,390
Accumulated other comprehensive loss	(17,988)	(19,094)
Total Equity	1,398,341	1,539,900	$ 1,468,119	$ 1,249,787
Total Liabilities and Equity	2,851,922	3,021,403
Parent Company
Assets
Investment in subsidiary	1,398,341	1,539,900
Total Assets	1,398,341	1,539,900
Liabilities and Equity
Total Liabilities	0	0
Equity:
Common stock, $0.01 par value, 1,000,000,000 shares authorized, 33,665,258 and 34,859,033 shares issued and outstanding, respectively	338	350
Additional paid-in capital	526,600	509,254
Retained earnings	889,391	1,049,390
Accumulated other comprehensive loss	(17,988)	(19,094)
Total Equity	1,398,341	1,539,900
Total Liabilities and Equity	$ 1,398,341	$ 1,539,900