Regulatory Matters (Tables)

12 Months Ended

Sep. 30, 2025

Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]

Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations

The following tables compare the Bank’s actual capital amounts at September 30, 2025 and 2024 to its minimum regulatory capital requirements and "Well Capitalized" regulatory capital at those dates (dollars in thousands):

	Actual				Regulatory Minimum To Be "Adequately Capitalized"				Regulatory Minimum To Be "Well Capitalized" Under Prompt Corrective Action Provisions
September 30, 2025	Amount		Ratio		Amount		Ratio		Amount		Ratio
Leverage Capital Ratio:
Tier 1 capital	$	247,162	12.5	%	$	79,319	4.0	%	$	99,148	5.0	%
Risk-based Capital Ratios:
CET1	247,162		19.3		57,623		4.5		83,234		6.5
Tier 1 capital	247,162		19.3		76,831		6.0		102,442		8.0
Total capital	263,200		20.6		102,442		8.0		128,052		10.0

September 30, 2024
Leverage Capital Ratio:
Tier 1 capital	$	229,206	12.0	%	$	76,319	4.0	%	$	95,399	5.0	%
Risk-based Capital Ratios:
CET1	229,206		18.0		57,318		4.5		82,793		6.5
Tier 1 capital	229,206		18.0		76,424		6.0		101,899		8.0
Total capital	245,152		19.3		101,899		8.0		127,374		10.0

The following table presents for informational purposes the regulatory capital ratios for Timberland Bancorp at September 30, 2025 and 2024 assuming that Timberland Bancorp was subject to regulatory guidelines for bank holding companies with $3.0 billion or more in assets (dollars in thousands):

	2025				2024
	Amount		Ratio		Amount		Ratio
Leverage Capital Ratio:
Tier 1 capital	$	248,755	12.6	%	$	231,092	12.1	%
Risk-based Capital Ratios:
CET1	248,755		19.4		231,092		18.1
Tier 1 capital	248,755		19.4		231,092		18.1
Total capital	264,800		20.7		247,044		19.4