Consolidated Statements Of Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative effect of adopting Accounting Standards Update ("ASU") 2022-02, net of tax [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Unearned Compensation ESOP [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative effect of adopting Accounting Standards Update ("ASU") 2022-02, net of tax [Member]	AOCI [Member]
Balance at Sep. 30, 2022	$ 1,096,499		$ 1,388	$ 1,190,213	$ (29,735)	$ 80,266		$ (145,633)
Net income	16,240					16,240
Other comprehensive income (loss), net of tax	13,031							13,031
ESOP activity	341			(72)	413
Stock-based compensation	89			89
Repurchase of common stock	(22,196)		(27)	(22,169)
Cash dividends to stockholders	(49,209)					(49,209)
Balance at Dec. 31, 2022	1,054,795		1,361	1,168,061	(29,322)	47,297		(132,602)
Balance at Sep. 30, 2023	1,044,054		1,359	1,166,643	(28,083)	(104,565)		8,700
Balance (Accounting Standards Update 2022-02 [Member]) at Sep. 30, 2023		$ (27)					$ (27)
Net income	2,543					2,543
Other comprehensive income (loss), net of tax	10,455							10,455
ESOP activity	222			(190)	412
Restricted stock activity, net	(6)			(6)
Stock-based compensation	87			87
Repurchase of common stock	(11,899)		(20)	(11,879)
Cash dividends to stockholders	(11,308)					(11,308)
Balance at Dec. 31, 2023	$ 1,034,121		$ 1,339	$ 1,154,655	$ (27,671)	$ (113,357)		$ 19,155