Investment Securities: Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Held to Maturity
Amortized Cost	$ 270,218	$ 266,608
Gross Unrealized Gains	295	260
Gross Unrealized Losses	(16,747)	(17,085)
Estimated Fair Value	253,766	249,783
Available for Sale
Total	43,132	42,309
Gross Unrealized Gains		0
Gross Unrealized Losses		894
Estimated Fair Value		41,415
U.S. agency securities
Held to Maturity
Amortized Cost	171,626	170,676
Gross Unrealized Gains	0	11
Gross Unrealized Losses	(10,088)	(12,109)
Estimated Fair Value	161,538	158,578
Mortgage-backed securities, U.S. government agencies
Held to Maturity
Amortized Cost	52,294	43,995
Gross Unrealized Gains	0	4
Gross Unrealized Losses	(3,950)	(2,486)
Estimated Fair Value	48,344	41,513
Available for Sale
Total	43,132	42,309
Gross Unrealized Gains	0	0
Gross Unrealized Losses	1,361	894
Estimated Fair Value	41,771	41,415
Mortgage-backed securities, Private label residential
Held to Maturity
Amortized Cost	44,011	49,335
Gross Unrealized Gains	295	245
Gross Unrealized Losses	(2,611)	(2,392)
Estimated Fair Value	41,695	47,188
Taxable municipal securities
Held to Maturity
Amortized Cost	1,787
Gross Unrealized Gains	0
Gross Unrealized Losses	(47)
Estimated Fair Value	1,740
Bank issued trust preferred securities
Held to Maturity
Amortized Cost	500	500
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(51)	(31)
Estimated Fair Value	$ 449	$ 469

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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