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Regulatory Matters: Narrative (Details) - Timberland Bank | Sep. 30, 2025 | Sep. 30, 2024
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Compliance with Regulatory Capital Requirements for Mortgage Companies [Line Items] |  |
Tier 1 Risk-based Capital Ratio, Regulatory Minimum To Be Adequately Capitalized, Ratio | 4.50% | 4.50%
Tier 1 Risk-based Capital, Regulatory Minimum To Be Adequately Capitalized, Ratio | 0.060 | 0.060
Total Capital, Regulatory Minimum To Be Adequately Capitalized, Ratio | 0.080 | 0.080
Tier 1 Leverage Capital, Regulatory Minimum To Be Adequately Capitalized, Ratio | 0.040 | 0.040

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- Definition Ratio of minimum total risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 505 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477270/942-505-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 505 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org/1943274/2147477270/942-505-50-1B + Details
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