Employee Benefit Plans (Narrative) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2025 USD ($) h years $ / shares shares		Sep. 30, 2024 USD ($) shares		Sep. 30, 2023 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Voluntary contributions made to the defined benefit plan	$ 0		$ 0
Required minimum contribution made to the defined benefit plan during the fiscal year	0
Net actuarial losses, which have not been recognized as components of net periodic benefit costs	$ (4,680)		(4,484)		$ (11,862)
Redemption restrictions on Plan assets	0
Net actuarial losses that will be recognized in AOCI as components of net periodic benefit cost in fiscal year	$ 0
Age of employees to participate in ESOP, minimum (in years) | years	18
Number of hours worked by employees to participate in ESOP, minimum (in hours) | h	1,000
Total compensation expense related to ESOP	$ 5,667		5,628		5,761
Purchase of the Company's common stock by ESOP from proceeds of a loan from the Company (in shares) | shares	11,605,824
Purchase of the Company's common stock by ESOP, (in usd per share) | $ / shares	$ 10
ESOP loan from the Company, outstanding principal balance	$ 28,571		$ 33,015
ESOP shares allocated to participants (in shares) | shares	9,439,128
ESOP shares committed to be released (in shares) | shares	325,005
ESOP shares unallocated or not yet committed to be released (in shares) | shares	1,841,691		2,275,031
ESOP shares that are unallocated or not yet committed to be released, fair market value	$ 29,974
Defined Benefit Plan, Plan Assets, Payment for Settlement	0		$ 0
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease), as a result of assumption changes	(3,502)
Fair Value of Plan Assets	76,809	[1]	81,216	[2]
Expected future benefit payment	9,620
Minimum employer contributions expected to be paid during the fiscal year ending September 30, 2026	$ 0
Defined Benefit Plan, Description	The Company’s Board of Directors approved the termination of the Plan, effective December 31, 2025, with the final transfer of assets expected within nine to 12 months of plan termination. In anticipation of the plan termination, certain assumptions were changed to determine the projected benefit obligation which include the following:•Retirees and 20% of active and terminated vested participants are valued assuming a group annuity purchase.•The remaining 80% of active and terminated vested participants are valued assuming lump sum payments, using prescribed lump sum segment rates for August 2025 and the prescribed mortality assumption for 2025.Those assumption changes resulted in a net decrease of $3,502 in the benefit obligation at September 30, 2025. The company is in the process of notifying plan participants and the appropriate regulatory bodies. The termination is not expected to have any material impact on the Company's liquidity or capital resources.
Active and Terminated Vested Participants are Valued Assuming a Group Annuity Purchase, Percentage	20.00%
Active and Terminated Vested Participants are Valued Assuming Lump Sum Payments, Percentage	80.00%
401(k)
Defined Benefit Plan Disclosure [Line Items]
Total of the Company's matching and discretionary contributions related to the 401(k) plan	$ 4,070		3,404		$ 4,297
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Plan assets target allocation, Percentage	20.00%
Fair Value of Plan Assets	$ 7,878		594
Excluded Unsettled Securities
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 1,382		$ 1,094
LDI Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets target allocation, Percentage	80.00%		80.00%
Equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets target allocation, Percentage			20.00%
401(k) First Tier
Defined Benefit Plan Disclosure [Line Items]
Allowable percentage of compensation, of eligible employees, to be contributed to the 401(k) plan	75.00%
401(k), Company match percentage of up to 4% of employee contributed funds	100.00%
401(k)
Defined Benefit Plan Disclosure [Line Items]
401(k), Company matched contributions, minimum vesting period	immediately
401(k), Company matched contributions, maximum vesting period	5 years
Maximum
Defined Benefit Plan Disclosure [Line Items]
Transfer of Assets from Termination of Plan, Months	12 months
Maximum | 401(k) First Tier
Defined Benefit Plan Disclosure [Line Items]
401(k), Percentage of funds contributed by employees to be matched 100% by the Company, maximum	4.00%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Transfer of Assets from Termination of Plan, Months	9 months

[1] Plan assets measured at fair value on a recurring basis excludes approximately $1,382 of net unsettled security transactions.

[2] (1) Plan assets measured at fair value on a recurring basis excludes approximately 1,094 of net unsettled security transactions