Regulatory Matters: Schedule of Compliance with Regulatory Capital Requirements for Mortgage Companies (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Timberland Bancorp
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage capital, Actual Amount	$ 85,158	$ 85,455
Tier 1 leverage capital, Actual Ratio	11.50%	11.70%
Tier 1 leverage capital, Capital Adequacy Purposes Amount	29,677	29,313
Tier 1 leverage capital, Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier 1 risk adjusted capital, Actual Amount	85,158	85,455
Tier 1 risk adjusted capital, Actual Ratio	15.30%	15.50%
Tier 1 risk adjusted capital, Capital Adequacy Purposes Amount	22,259	22,042
Tier 1 risk adjusted capital, Capital Adequacy Purposes Ratio	4.00%	4.00%
Tier 1 risk based capital, Actual Amount	92,168	92,406
Tier 1 risk based capital, Actual Ratio	16.60%	16.80%
Total risk based capital, Capital Adequacy Purposes Amount	44,518	44,084
Total risk based capital, Capital Adequacy Purposes Ratio	8.00%	8.00%
Timberland Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage capital, Actual Amount	82,265	79,911
Tier 1 leverage capital, Actual Ratio	11.10%	10.90%
Tier 1 leverage capital, Capital Adequacy Purposes Amount	29,662	73,013
Tier 1 leverage capital, Capital Adequacy Purposes Ratio	4.00%	10.00%
Tier 1 leverage capital, To be Well Capitalized Under Prompt Corrective Action Provisions Amount	37,078	73,013
Tier 1 leverage capital, To be Well Capitalized Under Prompt Corrective Action Provisions Ratio	5.00%	10.00%
Tier 1 risk adjusted capital, Actual Amount	82,265	79,911
Tier 1 risk adjusted capital, Actual Ratio	14.80%	14.50%
Tier 1 risk adjusted capital, Capital Adequacy Purposes Amount	22,255	33,036
Tier 1 risk adjusted capital, Capital Adequacy Purposes Ratio	4.00%	6.00%
Tier 1 risk adjusted capital, To be Well Capitalized Under Prompt Corrective Action Provisions Amount	33,382	33,036
Tier 1 risk adjusted capital, To be Well Capitalized Under Prompt Corrective Action Provisions Ratio	6.00%	6.00%
Tier 1 risk based capital, Actual Amount	89,273	86,856
Tier 1 risk based capital, Actual Ratio	16.10%	15.80%
Total risk based capital, Capital Adequacy Purposes Amount	44,509	55,059
Total risk based capital, Capital Adequacy Purposes Ratio	8.00%	10.00%
Total risk based capital, To be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 55,636	$ 55,059
Total risk based capital, To be Well Capitalized Under Prompt Corrective Action Provisions Ratio	10.00%	10.00%

Tier One Risk Adjusted Capital

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Tier One Risk Adjusted Capital Required For Capital Adequacy

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Tier One Risk Adjusted Capital Required For Capital Adequacy To Risk Weighted Assets

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Tier One Risk Adjusted Capital Required To Be Well Capitalized

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Tier One Risk Adjusted Capital Required To Be Well Capitalized To Risk Weighted Assets

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Tier One Risk Adjusted Capital To Risk Weighted Assets

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Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

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The minimum amount of Tier 1 Leverage Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action.

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Tier 1 Leverage Capital divided by average assets as defined in the regulations.

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Tier 1 Risk Based Capital as defined in the regulations.

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The minimum amount of Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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