RECENT DEVELOPMENTS AND SIGNIFICANT EVENTS	12 Months Ended
Dec. 31, 2013
Recent Developments and Significant Events [Abstract]
RECENT DEVELOPMENTS AND SIGNIFICANT EVENTS	RECENT DEVELOPMENTS AND SIGNIFICANT EVENTS Proposed Acquisition of Six Sterling Savings Bank Branches On February 19, 2014, the Company announced that Banner Bank had entered into an agreement for the acquisition of six branches in Oregon from Sterling Savings Bank. The purchase of the branches is subject to consummation of the previously announced merger between Sterling Financial Corporation, the parent of Sterling Savings Bank, and Umpqua Holdings Corporation, regulatory approval and the satisfaction of customary closing conditions and is expected to be completed in the second quarter of 2014. Canceled Acquisition of Home Federal Bancorp, Inc. On September 24, 2013, the Company and Home Federal Bancorp, Inc. (NASDAQ: HOME), announced the signing of a definitive Agreement and Plan of Merger. The Agreement allowed a thirty-day period during which the board of directors of Home Federal Bancorp, Inc. could evaluate purchase offers from other institutions. On October 16, 2013, Home Federal Bancorp, Inc.'s board declared that it had received a superior proposal from Cascade Bancorp. Under the terms of the Agreement, Banner's board of directors had the right but elected not to match Cascade's offer. Consequently, on October 23, 2013, Banner announced that the Agreement between it and Home Federal Bancorp, Inc. had been terminated. In connection with the termination of the Agreement, Home Federal Bancorp, Inc. paid a termination fee of $3.0 million to Banner. Income Tax Reporting and Accounting: Amended Federal Income Tax Returns: The Company has years 2010 - 2012 open for tax examination under the statute of limitation provisions of the Internal Revenue Code of 1986 (Code). Tax years 2006 - 2009 are not open for assessment of additional tax, but remain open for adjustment to the amount of Net Operating Losses (NOLs), credit, and other carryforwards utilized in open years or to be utilized in the future. The Company filed amended federal income tax returns for tax years 2008 and 2009 to claim additional bad debt deductions, which resulted in additional NOLs for tax years 2008 and 2009. The Company also filed amended federal income tax returns for tax years 2005 - 2006 and a tentative refund claim for tax year 2007 to carryback the NOLs and general business credits from 2008 and 2009 to those earlier years. Review of the amended returns for all years was completed by the Internal Revenue Service (IRS) and the Company signed a closing agreement with the IRS related to refund claims of $9.8 million, primarily related to tax year 2006. During the year ended December 31, 2013 the Company recorded a tax receivable of $9.8 million with an offsetting adjustment to its deferred tax assets. Additionally, the Company recorded an estimated amount for interest on the tax receivable of $450,000 in 2013, which was recorded in miscellaneous income. Deferred Tax Asset Valuation Allowance: The Company and its wholly-owned subsidiaries file consolidated U.S. federal income tax returns, as well as state income tax returns in Oregon and Idaho. Income taxes are accounted for using the asset and liability method. Under this method a deferred tax asset or liability is determined based on the enacted tax rates which are expected to be in effect when the differences between the financial statement carrying amounts and tax basis of existing assets and liabilities are expected to be reported in the Company’s income tax returns. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. Under GAAP, a valuation allowance is required to be recognized if it is “more likely than not” that all or a portion of Banner’s deferred tax assets will not be realized. During 2010, the Company evaluated its net deferred tax asset and determined it was prudent to establish a full valuation allowance against the net asset. While the full valuation allowance remained in effect, the Company did not recognize any tax expense or benefit in its Consolidated Statements of Operations. During 2012, management analyzed the Company’s performance and trends since December 31, 2010, focusing on trends in asset quality, loan loss provisioning, capital position, net interest margin, core operating income and net income and the likelihood of continued profitability. Based on this analysis, management determined that a full valuation allowance was no longer appropriate and reversed all of the valuation allowance during the year ending December 31, 2012. The ultimate realization of deferred tax assets is dependent upon the existence, or generation, of taxable income in the periods when those temporary differences and net operating loss and credit carryforwards are deductible. See Note 13 of the Notes to the Consolidated Financial Statements for more information. Stockholder Equity Transactions: Preferred Stock: On March 29, 2012, the Company’s $124 million of Series A Preferred Stock with a liquidation value of $1,000 per share, originally issued to the U.S. Treasury (Treasury) as part of its Capital Purchase Program, was sold by the Treasury as part of its efforts to manage and recover its investments under the Troubled Asset Relief Program (TARP). While the sale of these preferred shares to new owners did not result in any proceeds to the Company and did not change the Company’s capital position or accounting for these securities, it did eliminate restrictions put in place by the Treasury on TARP recipients. During the year ended December 31, 2012, the Company repurchased or redeemed all of its Series A Preferred Stock. The related warrants to purchase up to $18.6 million in Banner common stock (243,998 shares) were sold by the Treasury at public auction in June 2013. That sale did not change the Company's capital position and did not have any impact on the financial accounting and reporting for these securities. Restricted Stock Grants: Under the 2012 Restricted Stock Plan, which was approved on April 24, 2012, the Company is authorized to issue up to 300,000 shares of its common stock to provide a means for attracting and retaining highly skilled officers of Banner Corporation and its affiliates. Shares granted under the Plan have a minimum vesting period of three years. The Plan will continue in effect for a term of ten years, after which no further awards may be granted. Vesting requirements may include time-based conditions, performance-based conditions, or market-based conditions. The 2012 Restricted Stock Plan was amended on April 23, 2013 to provide for the ability to grant (1) cash-denominated incentive-based awards payable in cash or common stock, including those that are eligible to qualify as qualified performance-based compensation for the purposes of Section 162(m) of the Code and (2) restricted stock awards that qualify as qualified performance-based compensation for the purposes of Section 162(m) of the Code. As of December 31, 2013, the Company had granted 189,426 shares of restricted stock from the 2012 Restricted Stock Plan, of which 31,178 shares had vested and 158,248 shares remain unvested.

RECENT DEVELOPMENTS AND SIGNIFICANT EVENTS

Proposed Acquisition of Six Sterling Savings Bank Branches

On February 19, 2014, the Company announced that Banner Bank had entered into an agreement for the acquisition of six branches in Oregon from Sterling Savings Bank. The purchase of the branches is subject to consummation of the previously announced merger between Sterling Financial Corporation, the parent of Sterling Savings Bank, and Umpqua Holdings Corporation, regulatory approval and the satisfaction of customary closing conditions and is expected to be completed in the second quarter of 2014.

Canceled Acquisition of Home Federal Bancorp, Inc.

On September 24, 2013, the Company and Home Federal Bancorp, Inc. (NASDAQ: HOME), announced the signing of a definitive Agreement and Plan of Merger. The Agreement allowed a thirty-day period during which the board of directors of Home Federal Bancorp, Inc. could evaluate purchase offers from other institutions. On October 16, 2013, Home Federal Bancorp, Inc.'s board declared that it had received a superior proposal from Cascade Bancorp. Under the terms of the Agreement, Banner's board of directors had the right but elected not to match Cascade's offer. Consequently, on October 23, 2013, Banner announced that the Agreement between it and Home Federal Bancorp, Inc. had been terminated. In connection with the termination of the Agreement, Home Federal Bancorp, Inc. paid a termination fee of $3.0 million to Banner.

Income Tax Reporting and Accounting:

Amended Federal Income Tax Returns: The Company has years 2010 - 2012 open for tax examination under the statute of limitation provisions of the Internal Revenue Code of 1986 (Code). Tax years 2006 - 2009 are not open for assessment of additional tax, but remain open for adjustment to the amount of Net Operating Losses (NOLs), credit, and other carryforwards utilized in open years or to be utilized in the future. The Company filed amended federal income tax returns for tax years 2008 and 2009 to claim additional bad debt deductions, which resulted in additional NOLs for tax years 2008 and 2009. The Company also filed amended federal income tax returns for tax years 2005 - 2006 and a tentative refund claim for tax year 2007 to carryback the NOLs and general business credits from 2008 and 2009 to those earlier years. Review of the amended returns for all years was completed by the Internal Revenue Service (IRS) and the Company signed a closing agreement with the IRS related to refund claims of $9.8 million, primarily related to tax year 2006. During the year ended December 31, 2013 the Company recorded a tax receivable of $9.8 million with an offsetting adjustment to its deferred tax assets. Additionally, the Company recorded an estimated amount for interest on the tax receivable of $450,000 in 2013, which was recorded in miscellaneous income.

Deferred Tax Asset Valuation Allowance: The Company and its wholly-owned subsidiaries file consolidated U.S. federal income tax returns, as well as state income tax returns in Oregon and Idaho. Income taxes are accounted for using the asset and liability method. Under this method a deferred tax asset or liability is determined based on the enacted tax rates which are expected to be in effect when the differences between the financial statement carrying amounts and tax basis of existing assets and liabilities are expected to be reported in the Company’s income tax returns. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. Under GAAP, a valuation allowance is required to be recognized if it is “more likely than not” that all or a portion of Banner’s deferred tax assets will not be realized. During 2010, the Company evaluated its net deferred tax asset and determined it was prudent to establish a full valuation allowance against the net asset. While the full valuation allowance remained in effect, the Company did not recognize any tax expense or benefit in its Consolidated Statements of Operations. During 2012, management analyzed the Company’s performance and trends since December 31, 2010, focusing on trends in asset quality, loan loss provisioning, capital position, net interest margin, core operating income and net income and the likelihood of continued profitability. Based on this analysis, management determined that a full valuation allowance was no longer appropriate and reversed all of the valuation allowance during the year ending December 31, 2012. The ultimate realization of deferred tax assets is dependent upon the existence, or generation, of taxable income in the periods when those temporary differences and net operating loss and credit carryforwards are deductible. See Note 13 of the Notes to the Consolidated Financial Statements for more information.

Stockholder Equity Transactions:

Preferred Stock: On March 29, 2012, the Company’s $124 million of Series A Preferred Stock with a liquidation value of $1,000 per share, originally issued to the U.S. Treasury (Treasury) as part of its Capital Purchase Program, was sold by the Treasury as part of its efforts to manage and recover its investments under the Troubled Asset Relief Program (TARP). While the sale of these preferred shares to new owners did not result in any proceeds to the Company and did not change the Company’s capital position or accounting for these securities, it did eliminate restrictions put in place by the Treasury on TARP recipients. During the year ended December 31, 2012, the Company repurchased or redeemed all of its Series A Preferred Stock. The related warrants to purchase up to $18.6 million in Banner common stock (243,998 shares) were sold by the Treasury at public auction in June 2013. That sale did not change the Company's capital position and did not have any impact on the financial accounting and reporting for these securities.

Restricted Stock Grants: Under the 2012 Restricted Stock Plan, which was approved on April 24, 2012, the Company is authorized to issue up to 300,000 shares of its common stock to provide a means for attracting and retaining highly skilled officers of Banner Corporation and its affiliates. Shares granted under the Plan have a minimum vesting period of three years. The Plan will continue in effect for a term of ten years, after which no further awards may be granted. Vesting requirements may include time-based conditions, performance-based conditions, or market-based conditions. The 2012 Restricted Stock Plan was amended on April 23, 2013 to provide for the ability to grant (1) cash-denominated incentive-based awards payable in cash or common stock, including those that are eligible to qualify as qualified performance-based compensation for the purposes of Section 162(m) of the Code and (2) restricted stock awards that qualify as qualified performance-based compensation for the purposes of Section 162(m) of the Code. As of December 31, 2013, the Company had granted 189,426 shares of restricted stock from the 2012 Restricted Stock Plan, of which 31,178 shares had vested and 158,248 shares remain unvested.