Acquisitions	6 Months Ended
Mar. 31, 2012
Business Combinations [Abstract]
Acquisitions	Acquisitions Western National Bank Effective December 16, 2011, Washington Federal, acquired certain assets and liabilities, including most of the loans and deposits, of Western National Bank, headquartered in Phoenix, Arizona (“WNB”) from the Federal Deposit Insurance Corporation (“FDIC”) in an FDIC assisted transaction. Under the terms of the Purchase and Assumption Agreement, the Bank and the FDIC agreed to a discount of $53 million on net assets and no loss sharing provision or premium on deposits. WNB operated three full-service offices in Arizona. The Bank acquired certain assets with a book value of $177 million, including $143 million in loans and $7 million in foreclosed real estate, and selected liabilities with a book value of $153 million, including $136 million in deposits. Pursuant to the purchase and assumption agreement with the FDIC, the Bank received a cash payment from the FDIC for $30 million. The acquisition was accounted for under the acquisition method of accounting. The purchased assets and assumed liabilities were recorded at their respective acquisition date estimated fair values. The purchase accounting for acquired assets and liabilities, mainly related to the valuation of the acquired loans, is subject to future adjustment based on the completion of valuations. The amounts currently recognized in the financial statements have been determined provisionally as we are completing a fair value analysis of those assets. Final purchase accounting adjustments are expected to be complete by fiscal year end. Loans that were classified as non-performing loans by WNB are no longer classified as non-performing because, at acquisition, the carrying value of these loans was adjusted to reflect fair value. Management believes that the new book value reflects an amount that will ultimately be collected. South Valley Bancorp, Inc. On April 4, 2012, the Company and South Valley Bancorp, Inc. (“South Valley”) announced the signing of a definitive merger agreement. The merger agreement calls for the merger of South Valley with and into the Company, followed by the merger of South Valley's wholly owned subsidiary, South Valley Bank & Trust, into the Company's wholly owned subsidiary, Washington Federal. Under the terms of the definitive merger agreement, each outstanding share of South Valley common stock will be converted into the right to receive: (i) 0.2962 of a share of the Company's common stock, (ii) a contingent cash payment equal to the pro rata portion of an earn-out from the net proceeds collected from a pool of specified assets of South Valley with a value of approximately $39 million as of March 31, 2012, and (iii) a contingent cash payment equal to the pro rata portion of the net proceeds, if any, received by South Valley from the sale of its trust business and/or wealth management business prior to the closing of the merger. Assuming a per share price of $16.88 for the Company's common stock, the aggregate value of the stock portion of the merger consideration is approximately $33.7 million. After consummation of the merger, the combined company will have 190 offices in eight western states with total assets of approximately $14.4 billion and total deposits of approximately $9.6 billion, based on financial results as of December 31, 2011. The merger is expected to close in the third calendar quarter of 2012, pending the receipt of all requisite regulatory approvals, the approval of South Valley's shareholders and the satisfaction of other customary closing conditions.

Acquisitions

6 Months Ended

Mar. 31, 2012

Western National Bank

Effective December 16, 2011, Washington Federal, acquired certain assets and liabilities, including most of the loans and deposits, of Western National Bank, headquartered in Phoenix, Arizona (“WNB”) from the Federal Deposit Insurance Corporation (“FDIC”) in an FDIC assisted transaction. Under the terms of the Purchase and Assumption Agreement, the Bank and the FDIC agreed to a discount of $53 million on net assets and no loss sharing provision or premium on deposits.

WNB operated three full-service offices in Arizona. The Bank acquired certain assets with a book value of $177 million, including $143 million in loans and $7 million in foreclosed real estate, and selected liabilities with a book value of $153 million, including $136 million in deposits. Pursuant to the purchase and assumption agreement with the FDIC, the Bank received a cash payment from the FDIC for $30 million.

The acquisition was accounted for under the acquisition method of accounting. The purchased assets and assumed liabilities were recorded at their respective acquisition date estimated fair values. The purchase accounting for acquired assets and liabilities, mainly related to the valuation of the acquired loans, is subject to future adjustment based on the completion of valuations. The amounts currently recognized in the financial statements have been determined provisionally as we are completing a fair value analysis of those assets. Final purchase accounting adjustments are expected to be complete by fiscal year end. Loans that were classified as non-performing loans by WNB are no longer classified as non-performing because, at acquisition, the carrying value of these loans was adjusted to reflect fair value. Management believes that the new book value reflects an amount that will ultimately be collected.

South Valley Bancorp, Inc.

On April 4, 2012, the Company and South Valley Bancorp, Inc. (“South Valley”) announced the signing of a definitive merger agreement. The merger agreement calls for the merger of South Valley with and into the Company, followed by the merger of South Valley's wholly owned subsidiary, South Valley Bank & Trust, into the Company's wholly owned subsidiary, Washington Federal. Under the terms of the definitive merger agreement, each outstanding share of South Valley common stock will be converted into the right to receive: (i) 0.2962 of a share of the Company's common stock, (ii) a contingent cash payment equal to the pro rata portion of an earn-out from the net proceeds collected from a pool of specified assets of South Valley with a value of approximately $39 million as of March 31, 2012, and (iii) a contingent cash payment equal to the pro rata portion of the net proceeds, if any, received by South Valley from the sale of its trust business and/or wealth management business prior to the closing of the merger. Assuming a per share price of $16.88 for the Company's common stock, the aggregate value of the stock portion of the merger consideration is approximately $33.7 million. After consummation of the merger, the combined company will have 190 offices in eight western states with total assets of approximately $14.4 billion and total deposits of approximately $9.6 billion, based on financial results as of December 31, 2011. The merger is expected to close in the third calendar quarter of 2012, pending the receipt of all requisite regulatory approvals, the approval of South Valley's shareholders and the satisfaction of other customary closing conditions.