Consolidated Statements Of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Unearned Compensation ESOP [Member]	Retained Earnings [Member]	AOCI [Member]
Balance at Sep. 30, 2021	$ 1,242,273	$ 1,388	$ 1,189,633	$ (31,387)	$ 98,944	$ (16,305)
Net income	22,186				22,186
Other comprehensive income (loss), net of tax	(7,021)					(7,021)
ESOP activity	487		74	413
Restricted stock activity, net	(3)		(3)
Stock-based compensation	123		123
Cash dividends to stockholders	(41,385)				(41,385)
Balance at Dec. 31, 2021	1,216,660	1,388	1,189,827	(30,974)	79,745	(23,326)
Balance at Sep. 30, 2021	1,242,273	1,388	1,189,633	(31,387)	98,944	(16,305)
Net income	64,961
Other comprehensive income (loss), net of tax						(85,620)
Balance at Jun. 30, 2022	1,131,740	1,388	1,190,117	(30,148)	72,308	(101,925)
Balance at Dec. 31, 2021	1,216,660	1,388	1,189,827	(30,974)	79,745	(23,326)
Net income	21,623				21,623
Other comprehensive income (loss), net of tax	(52,581)					(52,581)
ESOP activity	461		48	413
Stock-based compensation	124		124
Cash dividends to stockholders	(11,535)				(11,535)
Balance at Mar. 31, 2022	1,174,752	1,388	1,189,999	(30,561)	89,833	(75,907)
Net income	21,152				21,152
Other comprehensive income (loss), net of tax	(26,018)					(26,018)
ESOP activity	408		(5)	413
Restricted stock activity, net	(3)		(3)
Stock-based compensation	126		126
Cash dividends to stockholders	(38,677)				(38,677)
Balance at Jun. 30, 2022	1,131,740	1,388	1,190,117	(30,148)	72,308	(101,925)
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, 2022	1,096,499	1,388	1,190,213	(29,735)	80,266	(145,633)
Net income	38,731
Other comprehensive income (loss), net of tax						18,927
Balance at Jun. 30, 2023	1,061,285	1,361	1,167,979	(28,497)	47,148	(126,706)
Balance at Dec. 31, 2022	1,054,795	1,361	1,168,061	(29,322)	47,297	(132,602)
Net income	14,189				14,189
Other comprehensive income (loss), net of tax	13,959					13,959
ESOP activity	336		(76)	412
Stock-based compensation	74		74
Cash dividends to stockholders	(11,319)				(11,319)
Balance at Mar. 31, 2023	1,072,034	1,361	1,168,059	(28,910)	50,167	(118,643)
Net income	8,302				8,302
Other comprehensive income (loss), net of tax	(8,063)					(8,063)
ESOP activity	258		(155)	413
Stock-based compensation	75		75
Cash dividends to stockholders	(11,321)				(11,321)
Balance at Jun. 30, 2023	$ 1,061,285	$ 1,361	$ 1,167,979	$ (28,497)	$ 47,148	$ (126,706)