Banner (BANR) 10-K 27 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Jan. 31, 2017	Jun. 30, 2016
Document Information [Line Items]
Entity Registrant Name	Banner Corporation
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Amendment Flag	false
Entity Central Index Key	946,673
Current Fiscal Year End Date	--12-31
Entity Public Float			$ 1,434,750,706
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Voting Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		33,108,767
Nonvoting Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		84,788

CONSOLIDATED STATEMENTS OF FINA

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
ASSETS
Cash and due from banks	$ 177,083	$ 117,657
Interest-bearing Deposits in Banks and Other Financial Institutions	70,636	144,260
Cash and Cash Equivalents, at Carrying Value	247,719	261,917
Securities—trading, amortized cost $30,154 and $39,344, respectively	24,568	34,134
Securities—available-for-sale, amortized cost $806,336 and $1,139,740, respectively	800,917	1,138,573
Securities—held-to-maturity, fair value $270,528 and $226,627, respectively	267,873	220,666
Federal Home Loan Bank (FHLB) stock	12,506	16,057
Loans Receivable Held-for-sale, Amount	246,353	44,712
Loans receivable	7,451,148	7,314,504
Allowance for loan losses	(85,997)	(78,008)
Total loans, net	7,365,151	7,236,496
Accrued interest receivable	30,178	29,627
Real estate owned (REO), held for sale, net	11,081	11,627
Property and equipment, net	166,481	167,604
Goodwill	244,583	247,738
Other intangible assets, net	30,162	37,472
Bank-owned life insurance (BOLI)	158,936	156,865
Deferred tax assets, net	127,694	134,970
Other assets	59,466	57,840
Total assets	9,793,668	9,796,298
Deposits:
Non-interest-bearing	3,140,451	2,619,618
Interest-bearing transaction and savings accounts	3,935,630	4,081,580
Interest-bearing certificates	1,045,333	1,353,870
Total deposits	8,121,414	8,055,068
Advances from FHLB at fair value	54,216	133,381
Other borrowings	105,685	98,325
Junior subordinated debentures at fair value (issued in connection with Trust Preferred Securities)	95,200	92,480
Accrued expenses and other liabilities	71,369	76,511
Deferred compensation	40,074	40,474
Total liabilities	8,487,958	8,496,239
COMMITMENTS AND CONTINGENCIES (Note 23)
SHAREHOLDERS’ EQUITY
Preferred stock - $0.01 par value per share, 500,000 shares authorized; no shares issued and outstanding at December 31, 2016 and December 31, 2015	0	0
Retained earnings	95,328	39,615
Accumulated other comprehensive loss	(3,455)	(730)
Carrying value of shares held in trust for stock related compensation plans	(7,283)	(6,928)
Liability for common stock issued to deferred, stock related, compensation plans	7,283	6,928
Shareholders’ equity	1,305,710	1,300,059
Total liabilities and stockholders' equity	9,793,668	9,796,298
Voting Common Stock [Member]
SHAREHOLDERS’ EQUITY
Common stock and paid in capital	1,213,225	1,195,755
Nonvoting Common Stock [Member]
SHAREHOLDERS’ EQUITY
Common stock and paid in capital	$ 612	$ 65,419

CONSOLIDATED STATEMENTS OF FIN3

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
ASSETS
Securities—trading, amortized cost basis	$ 30,154	$ 39,344
Securities—available-for-sale, amortized cost basis	806,336	1,139,740
Held-to-maturity Securities, Fair Value	270,528	226,627
Loans Held-for-sale, Fair Value	$ 9,600	$ 0
SHAREHOLDERS’ EQUITY
Preferred stock, share par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares outstanding	0	0
Voting Common Stock [Member]
SHAREHOLDERS’ EQUITY
Common stock, share par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	33,108,599	32,817,789
Common stock, shares outstanding	33,108,599	32,817,789
Nonvoting Common Stock [Member]
SHAREHOLDERS’ EQUITY
Common stock, share par value	$ 0.01	$ 0.01
Common stock, shares authorized	5,000,000	5,000,000
Common stock, shares issued	84,788	1,424,466
Common stock, shares outstanding	84,788	1,424,466

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
INTEREST INCOME:
Loans receivable	$ 359,612	$ 237,292	$ 177,541
Mortgage-backed securities	19,328	9,049	5,779
Securities and cash equivalents	12,537	8,092	7,341
Total interest income	391,477	254,433	190,661
INTEREST EXPENSE:
Deposits	11,105	8,385	7,578
FHLB advances	953	311	125
Other borrowings	310	211	172
Junior subordinated debentures	4,040	3,247	2,914
Total interest expense	16,408	12,154	10,789
Net interest income before provision for loan losses	375,069	242,279	179,872
PROVISION FOR LOAN LOSSES	6,030	0	0
Net interest income	369,039	242,279	179,872
NON-INTEREST INCOME
Deposit fees and other service charges	49,156	40,607	30,553
Mortgage banking operations	25,552	17,720	10,249
Bank Owned Life Insurance Income	4,538	2,497	1,809
Miscellaneous	6,001	2,821	1,885
Other operating income	85,247	63,645	44,496
Net gain (loss) on sale of securities	843	(540)	42
Net change in valuation of financial instruments carried at fair value	(2,620)	(813)	1,374
Acquisition bargain purchase gain	0	0	9,079
Total non-interest income	83,470	62,292	54,991
NON-INTEREST EXPENSE:
Salary and employee benefits	180,883	127,282	89,778
Less capitalized loan origination costs	(18,895)	(14,379)	(11,730)
Occupancy and equipment	45,000	30,366	22,743
Information/computer data services	19,281	12,110	8,131
Payment and card processing expenses	21,604	16,430	11,460
Professional services	8,120	4,828	3,753
Advertising and marketing	9,709	7,649	6,266
Deposit insurance	4,551	3,189	2,415
State/municipal business and use taxes	3,516	1,889	1,437
REO operations	175	397	(446)
Amortization of core deposit intangibles	7,061	3,164	1,990
Miscellaneous	30,131	17,565	13,619
Total other operating expense, before acquisition related costs	311,136	210,490	149,416
Acquisition related costs	11,733	26,110	4,325
Total non-interest expense	322,869	236,600	153,741
Income before provision for income taxes	129,640	67,971	81,122
PROVISION FOR INCOME TAXES	44,255	22,749	27,052
NET INCOME	$ 85,385	$ 45,222	$ 54,070
Earnings per common share
Basic (in dollars per share)	$ 2.52	$ 1.90	$ 2.79
Diluted (in dollars per share)	2.52	1.89	2.79
Cumulative dividends declared per common share (in dollars per share)	$ 0.88	$ 0.72	$ 0.72
Weighted average number of common shares outstanding:
Basic	33,820,148	23,801,373	19,359,409
Diluted	33,853,511	23,866,621	19,402,656

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 85,385	$ 45,222	$ 54,070
OTHER COMPREHENSIVE INCOME (LOSS), NET OF INCOME TAXES:
Unrealized holding (loss) gain on securities—available-for-sale arising during the period	(3,940)	(645)	4,319
Income tax benefit (expense) related to securities—available-for-sale unrealized holding gains (losses)	1,414	249	(1,555)
Reclassification for net gains on securities—available-for-sale realized in earnings	(311)	(119)	(41)
Income tax benefit related to securities—available-for-sale realized gains	112	43	15
Other comprehensive income (loss)	(2,725)	(472)	2,738
COMPREHENSIVE INCOME	$ 82,660	$ 44,750	$ 56,808

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Common Stock Including Additional Paid in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Deferred Compensation, Share-based Payments [Member]
Balance, beginning of the period at Dec. 31, 2013	$ 538,331		$ 569,028	$ (25,714)	$ (2,996)	$ (1,987)
Balance, beginning of the period, shares at Dec. 31, 2013		19,543,769
Net income	54,070			54,070
Other comprehensive income (loss)	2,738				2,738
Accrual of dividends on common stock	(14,092)			(14,092)
Cash paid for repurchase of common stock	0
Redemption of unallocated shares upon termination of ESOP	0		(1,987)			1,987
Redemption of unallocated shares upon termination of ESOP, shares		(34,340)
Repurchase of shares upon termination of ESOP	(555)		(555)
Repurchase of shares upon termination of ESOP, shares		(13,550)
Proceeds from issuance of common stock for stockholder reinvestment program, net of registration expenses amount	127		127
Proceeds from issuance of common stock for stockholder reinvestment program shares		3,170
Amortization of share-based compensation related to restricted stock grants, net of shares surrendered	2,203		2,203
Issuance of unvested restricted common stock, net, shares		72,499
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	66
Balance, end of the period, shares at Dec. 31, 2014		19,571,548
Balance, end of the period at Dec. 31, 2014	582,888		568,882	14,264	(258)	0
Net income	45,222			45,222
Other comprehensive income (loss)	(472)				(472)
Accrual of dividends on common stock	(19,871)			(19,871)
Cash paid for repurchase of common stock	0
Proceeds from issuance of common stock for stockholder reinvestment program, net of registration expenses amount	34		34
Proceeds from issuance of common stock for stockholder reinvestment program shares		810
Amortization of share-based compensation related to restricted stock grants, net of shares surrendered	3,088		3,088
Issuance of unvested restricted common stock, net, shares		120,043
Stock Issued During Period, Value, Acquisitions	688,773
Stock Issued During Period, Shares, Acquisitions		14,549,854
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	397
Balance, end of the period, shares at Dec. 31, 2015		34,242,255
Balance, end of the period at Dec. 31, 2015	1,300,059		1,261,174	39,615	(730)	0
Net income	85,385			85,385
Other comprehensive income (loss)	(2,725)				(2,725)
Accrual of dividends on common stock	(29,672)			(29,672)
Cash paid for repurchase of common stock	(50,772)		50,772
Repurchase of shares upon termination of ESOP, shares		(1,145,250)
Amortization of share-based compensation related to restricted stock grants, net of shares surrendered	3,401		3,401
Issuance of unvested restricted common stock, net, shares		96,382
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	34
Balance, end of the period, shares at Dec. 31, 2016		33,193,387
Balance, end of the period at Dec. 31, 2016	$ 1,305,710		$ 1,213,837	$ 95,328	$ (3,455)	$ 0

CONSOLIDATED STATEMENTS OF CHA7

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Stockholders' Equity [Abstract]
Accrual of dividends on common share (dollars per share)	$ 0.23	$ 0.23	$ 0.21	$ 0.21	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.88	$ 0.72	$ 0.72

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES:
Net income	$ 85,385	$ 45,222	$ 54,070
Adjustments to reconcile net income to net cash provided from operating activities:
Depreciation	13,464	9,957	8,064
Deferred income and expense, net of amortization	(1,323)	(1,534)	1,541
Amortization of core deposit intangibles	7,061	3,164	1,990
Loss (gain) on sale of securities, net	(843)	540	(42)
Net change in valuation of financial instruments carried at fair value	2,620	813	(1,374)
Purchases of securities—trading	(1,725)	(6,338)	(2,387)
Proceeds from sales of securities—trading	7,839	4,419	2,387
Principal repayments and maturities of securities—trading	3,746	9,535	27,709
Bargain purchase gain on acquisition	0	0	(9,079)
(Increase) decrease in deferred taxes	7,883	(3,906)	2,966
(Decrease) increase in current taxes payable	(2,184)	(1,519)	11,771
Equity-based compensation	3,435	3,486	2,269
Increase in cash surrender value of BOLI	(4,507)	(2,481)	(1,788)
Gain on sale of loans, net of capitalized servicing rights	(17,713)	(10,716)	(6,080)
Gain on disposal of real estate held for sale and property and equipment	(1,389)	(391)	(1,076)
PROVISION FOR LOAN LOSSES	6,030	0	0
Provision for real estate held for sale	876	216	36
Origination of loans held for sale	(1,063,328)	(709,035)	(361,859)
Proceeds from sales of loans held for sale	880,890	677,166	367,888
Net change in:
Other assets	3,759	(7,319)	(2,310)
Other liabilities	(6,664)	4,090	3,370
Net cash (used by) provided from operating activities	(76,688)	15,369	98,066
INVESTING ACTIVITIES:
Purchases of securities—available-for-sale	(243,115)	(141,989)	(58,705)
Principal repayments and maturities of securities—available-for-sale	191,534	113,431	62,520
Proceeds from sales of securities—available-for-sale	369,755	232,620	56,267
Purchases of securities—held-to-maturity	(60,344)	(13,357)	(38,961)
Principal repayments and maturities of securities—held-to-maturity	11,009	12,978	9,194
Loan originations, net of repayments	(46,042)	(32,675)	(144,152)
Purchases of loans and participating interest in loans	(314,301)	(323,533)	(194,381)
Proceeds from sales of other loans	233,419	124,407	11,277
Net cash received from acquisitions, net of branch divestitures	0	24,208	127,557
Proceeds from Sale of Property, Plant, and Equipment	14,513	4,740	4,923
Purchases of property and equipment	(16,239)	(12,072)	(5,935)
Proceeds from FHLB stock repurchase program	80,681	48,843	8,354
Purchase of FHLB stock	(77,130)	(23,634)	0
Other	2,707	1,092	(2,025)
Net cash provided from (used by) investing activities	146,447	15,059	(164,067)
FINANCING ACTIVITIES:
Increase in deposits, net	66,346	226,821	68,938
Repayment of long term FHLB borrowing	(95,009)	(8)	(8)
Advances, net of (repayments) of overnight and short-term FHLB borrowings	16,400	(120,400)	5,000
Increase (decrease) in other borrowings, net	7,360	16,140	(5,871)
Cash dividends paid	(28,282)	(17,170)	(13,462)
Cash proceeds from issuance of shares for shareholder reinvestment plan	0	34	127
Cash paid for repurchase of common stock	(50,772)	0	0
Net cash (used by) provided from financing activities	(83,957)	105,417	54,724
NET CHANGE IN CASH AND CASH EQUIVALENTS	(14,198)	135,845	(11,277)
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	261,917	126,072	137,349
CASH AND CASH EQUIVALENTS, END OF YEAR	247,719	261,917	126,072
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest paid in cash	16,722	12,252	10,929
Taxes paid in cash	36,153	27,256	13,047
NON-CASH INVESTING AND FINANCING TRANSACTIONS:
Loans, net of discounts, specific loss allowances and unearned income, transferred to real estate owned and other repossessed assets	9,146	4,456	3,493
Dividends accrued but not paid until after period end	7,662	6,271	3,570
ACQUISITIONS (Note 3):
Assets acquired	0	4,829,748	221,206
Liabilities assumed	$ 0	$ 4,249,751	$ 212,127

BASIS OF PRESENTATION AND SUMMA

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Business: Banner Corporation (Banner or the Company) is a bank holding company incorporated in the State of Washington. The Company is primarily engaged in the business of planning, directing and coordinating the business activities of two wholly-owned subsidiaries, Banner Bank and Islanders Bank. Banner Bank is a Washington-chartered commercial bank that conducts business from its headquarters in Walla Walla, Washington and, as of December 31, 2016 , its 187 branch offices and 11 loan production offices located in Washington, Oregon, California, Utah and Idaho. Islanders Bank is also a Washington-chartered commercial bank that conducts business from three locations in San Juan County, Washington. Banner Corporation is subject to regulation by the Board of Governors of the Federal Reserve System (Federal Reserve Board). Banner Bank and Islanders Bank (the Banks) are subject to regulation by the Washington State Department of Financial Institutions, Division of Banks (DFI) and the Federal Deposit Insurance Corporation (the FDIC). The Company’s operating results depend primarily on its net interest income, which is the difference between interest income on interest-earning assets, consisting of loans and investment securities, and interest expense on interest-bearing liabilities, composed primarily of customer deposits, FHLB advances, other borrowings and junior subordinated debentures. Net income also is affected by the level of the Company’s non-interest income, including deposit fees and other service charges, gains and losses on the sale of securities, results of mortgage banking operations, which includes loan origination and servicing fees and gains and losses on the sale of loans, as well as non-interest expense, provisions for loan losses and income tax provisions. In addition, net income is affected by the net change in the value of certain financial instruments carried at fair value. Basis of Presentation and Principles of Consolidation: The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All material intercompany transactions, profits and balances have been eliminated. The consolidated financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States (GAAP) and under the rules and regulations of the U.S. Securities and Exchange Commission (the SEC). Subsequent Events: The Company has evaluated events and transactions subsequent to December 31, 2016 for potential recognition or disclosure. Cash and Cash Equivalents: Cash and cash equivalents include cash and due from banks and temporary investments which are federal funds sold and interest bearing balances due from other banks. Cash and cash equivalents generally have maturities of three months or less at the date of purchase. Business Combinations: Business combinations are accounted for using the acquisition method of accounting and, accordingly, assets acquired and liabilities assumed, both tangible and intangible, and consideration exchanged are recorded at acquisition date fair values. The excess purchase consideration over fair value of net assets acquired is recorded as goodwill. In the event that the fair value of net assets acquired exceeds the purchase price, including fair value of liabilities assumed, a bargain purchase gain is recorded on that acquisition. Expenses incurred in connection with a business combination are expensed as incurred. Changes in deferred tax asset valuation allowances related to acquired tax uncertainties are recognized in net income after the measurement period. Use of Estimates: In the opinion of management, the accompanying consolidated statements of financial condition and related consolidated statements of operations, comprehensive income, changes in shareholders’ equity and cash flows reflect all adjustments (which include reclassification and normal recurring adjustments) that are necessary for a fair presentation in conformity with GAAP. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect amounts reported in the financial statements. Various elements of the Company’s accounting policies, by their nature, are inherently subject to estimation techniques, valuation assumptions and other subjective assessments. In particular, management has identified several accounting policies that, due to the judgments, estimates and assumptions inherent in those policies, are critical to an understanding of Banner’s financial statements. These policies relate to (i) the methodology for the recognition of interest income, (ii) determination of the provision and allowance for loan and lease losses, (iii) the valuation of financial assets and liabilities recorded at fair value, including other-than-temporary impairment (OTTI) losses, (iv) the valuation of intangibles, such as goodwill, core deposit intangibles (CDI) and mortgage servicing rights, (v) the valuation of real estate held for sale, (vi) the valuation or recognition of deferred tax assets and liabilities and (vii) the valuation of assets and liabilities acquired in business combinations and subsequent recognition of related income and expense. These policies and judgments, estimates and assumptions are described in greater detail in subsequent Notes to the Consolidated Financial Statements. Management believes that the judgments, estimates and assumptions used in the preparation of the financial statements are appropriate based on the factual circumstances at the time. However, given the sensitivity of the financial statements to these critical accounting policies, the use of other judgments, estimates and assumptions could result in material differences in the Company’s results of operations or financial condition. Further, subsequent changes in economic or market conditions could have a material impact on these estimates and the Company’s financial condition and operating results in future periods. Securities: Securities are classified as held-to-maturity when the Company has the ability and positive intent to hold them to maturity. Securities classified as available-for-sale are available for future liquidity requirements and may be sold prior to maturity. Securities classified as trading are also available for future liquidity requirements and may be sold prior to maturity. Purchase premiums and discounts are recognized in interest income using the interest method over the terms of the securities. Securities classified as held-to-maturity are carried at cost, adjusted for amortization of premiums and accretion of discounts to maturity and, if appropriate, any other-than-temporary impairment losses. Securities classified as available-for-sale are recorded at fair value. Unrealized holding gains and losses on securities classified as available-for-sale are excluded from earnings and are reported net of tax as accumulated other comprehensive income (OCI), a component of shareholders’ equity, until realized. Securities classified as trading are also recorded at fair value. Unrealized holding gains and losses on securities classified as trading are included in earnings. (See Note 18 for a more complete discussion of accounting for the fair value of financial instruments.) Declines in the fair value of securities below their cost that are deemed to be other-than-temporary are recognized in earnings as realized losses. Realized gains and losses on sale are computed on the specific identification method and are included in earnings on the trade date sold. The Company reviews investment securities on an ongoing basis for the presence of OTTI or permanent impairment, taking into consideration current market conditions, fair value in relationship to cost, extent and nature of the change in fair value, issuer rating changes and trends, whether the Company intends to sell a security or if it is likely that it will be required to sell the security before recovery of the amortized cost basis of the investment, which may be maturity, and other factors. For debt securities, if the Company intends to sell the security or it is likely that the Company will be required to sell the security before recovering its cost basis, the entire impairment loss would be recognized in earnings as an OTTI. If the Company does not intend to sell the security and it is not likely that the Company will be required to sell the security but the Company does not expect to recover the entire amortized cost basis of the security, only the portion of the impairment loss representing credit losses would be recognized in earnings. The credit loss on a security is measured as the difference between the amortized cost basis and the present value of the cash flows expected to be collected. Projected cash flows are discounted by the original or current effective interest rate depending on the nature of the security being measured for potential OTTI. The remaining impairment related to all other factors, the difference between the present value of the cash flows expected to be collected and fair value, is recognized as a charge to OCI. Impairment losses related to all other factors are presented as separate categories within OCI. For investment securities transferred from held-to-maturity to available-for-sale, unrealized gains or losses from the time of transfer are accreted or amortized over the remaining life of the debt security based on the amount and timing of future estimated cash flows. The accretion or amortization of the amount recorded in OCI increases the carrying value of the investment and does not affect earnings. Investment in FHLB Stock: At December 31, 2016 , the Banks had $12.5 million in FHLB of Des Moines stock (FHLB stock), compared to $16.1 million at December 31, 2015 . The Banks' investments in FHLB stock are generally viewed as a long-term investment and are carried at par value ( $100 per share), which reasonably approximates its fair value. FHLB stock does not have a readily determinable fair value. Ownership of FHLB stock is restricted to the FHLB and member institutions and can only be purchased and redeemed at par. As members of the FHLB system, the Banks are required to maintain a minimum level of investment in FHLB stock based on specific percentages of their outstanding FHLB advances. Management periodically evaluates FHLB stock for impairment. Management's determination of whether these investments are impaired is based on its assessment of the ultimate recoverability of cost rather than by recognizing temporary declines in value. The determination of whether a decline affects the ultimate recoverability of cost is influenced by criteria such as (1) the significance of any decline in net assets of the FHLB as compared to the capital stock amount for the FHLB and the length of time this situation has persisted, (2) commitments by the FHLB to make payments required by law or regulation and the level of such payments in relation to the operating performance of the FHLB, (3) the impact of legislative and regulatory changes on institutions and, accordingly, the customer base of the FHLB, and (4) the liquidity position of the FHLB. The Company has determined there is no impairment on the FHLB stock investment as of December 31, 2016 . Loans Receivable: The Banks originate residential one- to four-family and multifamily mortgage loans for both portfolio investment and sale in the secondary market. The Banks also originate construction and land development, commercial real estate, commercial business, agricultural and consumer loans for portfolio investment. Loans receivable not designated as held for sale are recorded at the principal amount outstanding, net of allowance for loan losses, deferred fees, discounts and premiums. Premiums, discounts and deferred loan fees are amortized to maturity using the level-yield methodology. Some of the Company’s loans are reported as troubled debt restructures (TDRs). Loans are appropriately reported as TDRs when the Banks grant a concession(s) to a borrower experiencing financial difficulties that it would not otherwise consider. Examples of such concessions include forgiveness of principal or accrued interest, extending the maturity date(s) or providing a lower interest rate than would be normally available for a transaction of similar risk. As a result of these concessions, loans identified as TDRs are impaired as the Bank will not collect all amounts due, both principal and interest, in accordance with the terms of the original loan agreement. TDRs are accounted for in accordance with the Banks’ impaired loan accounting policies. Loans Held for Sale . Residential one- to four-family and multifamily mortgage loans with the intent to be sold in the secondary market are considered held for sale. Residential one- to four-family loans under best effort delivery commitments and multifamily mortgage loans are carried at the lower of aggregate cost or estimated market value. Residential one- to four-family loans under mandatory delivery commitments are carried at fair value in order to match changes in the value of the loans with the value of the economic hedges on the loans. Fair values for residential mortgage loans held for sale are determined by comparing actual loan rates to current secondary market prices for similar loans. Fair values for multifamily loans held for sale are calculated using recent sales data for comparable loans. Net unrealized losses on loans held for sale are recognized through a valuation allowance by charges to income. Non-refundable fees and direct loan origination costs related to loans held for sale are recognized as part of the cost basis of the loan. Gains and losses on sales of loans held for sale are determined using the specific identification method and are recorded in the mortgage banking operations component of non-interest income . Acquired Loans: Purchased loans, including loans acquired in business combinations, are recorded at their fair value at the acquisition date. Credit discounts are included in the determination of fair value; therefore, an allowance for loan and lease losses is not recorded at the acquisition date. Acquired loans are evaluated upon acquisition and classified as either purchased credit-impaired or purchased non-credit-impaired. Purchased credit-impaired (PCI) loans reflect credit deterioration since origination such that it is probable at acquisition that the Company will be unable to collect all contractually required payments. The excess of the cash flows expected to be collected over a PCI pool's carrying value is considered to be the accretable yield and is recognized as interest income over the estimated life of the pool using the effective yield method. The excess of the undiscounted contractual balances due over the cash flows expected to be collected is considered to be the nonaccretable difference. The nonaccretable difference represents the Company's estimate of the credit losses expected to occur and was considered in determining the fair value of the loans as of the acquisition date. Subsequent to the acquisition date, any increases in expected cash flows over those expected at purchase date in excess of fair value are adjusted through a change to the accretable yield on a prospective basis. Any subsequent decreases in expected cash flows attributable to credit deterioration are recognized by recording a provision for loan losses. For purchased non-credit-impaired loans, the difference between the fair value and unpaid principal balance of the loan at the acquisition date is amortized or accreted to interest income over the life of the loans. Any subsequent deterioration in credit quality is recognized by recording a provision for loan losses. Income Recognition on Nonaccrual and Impaired Loans and Securities: Interest on loans and securities is accrued as earned unless management doubts the collectability of the asset or the unpaid interest. Interest accruals on loans are generally discontinued when loans become 90 days past due for payment of interest or principal and the loans are then placed on nonaccrual status. All previously accrued but uncollected interest is deducted from interest income upon transfer to nonaccrual status. For any future payments collected, interest income is recognized only upon management’s assessment that there is a strong likelihood that the full amount of a loan will be repaid or recovered. A loan may be put on nonaccrual status sooner than this policy would dictate if, in management’s judgment, the interest may be uncollectable. While less common, similar interest reversal and nonaccrual treatment is applied to investment securities if their ultimate collectability becomes questionable. Provision and Allowance for Loan Losses: The provision for loan losses reflects the amount required to maintain the allowance for losses at an appropriate level based upon management’s evaluation of the adequacy of general and specific loss reserves. The Company maintains an allowance for loan losses consistent in all material respects with GAAP. The Company has established systematic methodologies for the determination of the adequacy of the Company’s allowance for loan losses. The methodologies are set forth in a formal policy and take into consideration the need for a general valuation allowance as well as specific allowances that are tied to individual problem loans. The Company increases its allowance for loan losses by charging provisions for probable loan losses against its income and values impaired loans consistent with accounting guidelines. The allowance for loan losses is maintained at a level sufficient to provide for estimated losses based on evaluating known and inherent risks in the loan portfolio and upon the Company’s continuing analysis of the factors underlying the quality of the loan portfolio. These factors include, among others, changes in the size and composition of the loan portfolio, delinquency rates, actual loan loss experience, current economic conditions, detailed analysis of individual loans for which full collectability may not be assured, and determination of the existence and realizable value of the collateral and guarantees securing the loans. Realized losses related to specific assets are applied as a reduction of the carrying value of the assets and charged immediately against the allowance for loan loss reserve. Recoveries on previously charged off loans are credited to the allowance for loan losses. The reserve is based upon factors and trends identified by Banner at the time financial statements are prepared. Although the Company uses the best information available, future adjustments to the allowance for loan losses may be necessary due to economic, operating, regulatory and other conditions beyond the Company’s control. The adequacy of general and specific reserves is based on a continuing evaluation of the pertinent factors underlying the quality of the loan portfolio as well as individual review of certain large balance loans. Large groups of smaller-balance homogeneous loans are collectively evaluated for impairment. Loans that are collectively evaluated for impairment include residential real estate and consumer loans and, as appropriate, smaller balance non-homogeneous loans. Larger balance non-homogeneous residential construction and land, commercial real estate, commercial business loans and unsecured loans are individually evaluated for impairment. Loans are considered impaired when, based on current information and events, the Company determines that it is probable that it will be unable to collect all amounts due according to the contractual terms of the loan agreement. Factors involved in determining impairment include, but are not limited to, the financial condition of the borrower and the value of the underlying collateral. Impaired loans are measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate or, as a practical expedient, at the loan’s observable market price, or if the loan is collateral dependent, at the fair value of collateral less selling costs. Subsequent changes in the value of impaired loans are included within the provision for loan losses in the same manner in which impairment initially was recognized or as a reduction in the provision that would otherwise be reported. The Company’s methodology for assessing the appropriateness of the allowance for loan losses consists of several key elements, which include specific allowances, an allocated formula allowance and an unallocated allowance. Losses on specific loans are provided for when the losses are probable and estimable. General loan loss reserves are established to provide for inherent loan portfolio risks not specifically provided for. The level of general reserves is based on analysis of potential exposures existing in the loan portfolio including evaluation of historical trends, current market conditions and other relevant factors identified by us at the time the financial statements are prepared. The formula allowance is calculated by applying loss factors to outstanding loans, excluding those loans that are subject to individual analysis for specific allowances. Loss factors are based on the Company’s historical loss experience adjusted for significant environmental considerations, including the experience of other banking organizations, which in the judgment of management affects the collectability of the loan portfolio as of the evaluation date. The unallocated allowance is based upon the Company’s evaluation of various factors that are not directly measured in the determination of the formula and specific allowances. While the Company believes the estimates and assumptions used in the determination of the adequacy of the allowance for loan losses are reasonable, there can be no assurance that such estimates and assumptions will not be proved incorrect in the future, or that the actual amount of future provisions will not exceed the amount of past provisions or that any increased provisions that may be required will not adversely impact the financial condition and results of operations of the Company. In addition, the determination of the amount of the allowance for loan losses is subject to review by bank regulators as part of the routine examination process, which may result in the adjustment of reserves based upon their judgment of information available to them at the time of their examination. Loan Origination and Commitment Fees: Loan origination fees, net of certain specifically defined direct loan origination costs, are deferred and recognized as an adjustment of the loans’ interest yield using the level-yield method over the contractual term of each loan adjusted for actual loan prepayment experience. Net deferred fees or costs related to loans held for sale are recognized as part of the cost basis of the loan. Loan commitment fees are deferred until the expiration of the commitment period unless management believes there is a remote likelihood that the underlying commitment will be exercised, in which case the fees are amortized to fee income using the straight-line method over the commitment period. If a loan commitment is exercised, the deferred commitment fee is accounted for in the same manner as a loan origination fee. Deferred commitment fees associated with expired commitments are recognized as fee income. Reserve for Unfunded Commitments: A reserve for unfunded commitments is maintained at a level that, in the opinion of management, is adequate to absorb probable losses associated with the Banks' commitments to lend funds under existing agreements such as letters or lines of credit. Management determines the adequacy of the reserve for unfunded commitments based upon reviews of individual credit facilities, current economic conditions, the risk characteristics of the various categories of commitments and other relevant factors. The reserve is based on estimates and ultimate losses may vary from the current estimates. These estimates are evaluated on a regular basis and, as adjustments become necessary, they are reported in earnings in the periods in which they become known. Draws on unfunded commitments that are considered uncollectible at the time funds are advanced are charged to the allowance for loan losses. Provisions for unfunded commitment losses are recognized in non-interest expense and added to the reserve for unfunded commitments, which is included in other liabilities. Real Estate Owned: Property acquired by foreclosure or deed in lieu of foreclosure is initially recorded at the estimated fair value of the property, less expected selling costs. Development and improvement costs relating to the property are capitalized while direct holding costs are expensed. The carrying value of the property is periodically evaluated by management and, if necessary, allowances are established to reduce the carrying value to net realizable value. Gains or losses at the time the property is sold are charged or credited to operations in the period in which they are realized. The amounts the Banks will ultimately recover from real estate held for sale may differ substantially from the carrying value of the assets because of market factors beyond the Banks’ control or because of changes in the Banks’ strategies for recovering the investment. Property and Equipment: Property and equipment is carried at cost less accumulated depreciation. The provision for depreciation is based upon the straight-line method applied to individual assets and groups of assets acquired in the same year over the lesser of their estimated useful lives or the related lease terms of the assets: Buildings and leased improvements 10–39 years Furniture and equipment 3 – 10 years Routine maintenance, repairs and replacement costs are expensed as incurred. Expenditures which significantly increase values or extend useful lives are capitalized. The Company reviews buildings, leasehold improvements and equipment for impairment whenever events or changes in circumstances indicate that the undiscounted cash flows for the property are less than its carrying value. If identified, an impairment loss is recognized through a charge to earnings based on the fair value of the property. Held for sale property is recorded at the lower of the estimated fair value of the property, less expected selling costs, or the book value at the date the property is transferred to held for sale. Depreciation is not recorded on held for sale property. Goodwill: Goodwill represents the excess of the purchase consideration over the fair value of the assets acquired, net of the fair values of liabilities assumed in a business combination and is not amortized but is reviewed annually, or more frequently as current circumstances and conditions warrant, for impairment. An assessment of qualitative factors is completed to determine if it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the qualitative analysis concludes that further analysis is required, then a quantitative impairment test would be completed. The quantitative goodwill impairment test is a two-step process. The first step compares the reporting unit's estimated fair values, including goodwill, to its carrying amount. If the carrying amount exceeds its fair value, then goodwill impairment may be indicated. The second step allocates the reporting units fair value to its assets and liabilities. If the unallocated fair value does not exceed the carrying amount of goodwill then an impairment loss would be recognized as a charge to earnings. Other Intangible Assets: Other intangible assets consist primarily of core deposit intangibles (CDI), which are amounts recorded in business combinations or deposit purchase transactions related to the value of transaction-related deposits and the value of the customer relationships associated with the deposits. CDI is being amortized on an accelerated basis over a weighted average estimated useful life of three to ten years. These assets are reviewed at least annually for events or circumstances that could impact their recoverability. These events could include loss of the underlying core deposits, increased competition or adverse changes in the economy. To the extent other identifiable intangible assets are deemed unrecoverable, impairment losses are recorded in other non-interest expense to reduce the carrying amount of the assets. Other intangibles also include favorable leasehold intangibles (LHI). LHI represents the value assigned to leases assumed in an acquisition in which the lease terms are favorable compared to a market lease at the date of acquisition. LHI is amortized over the underlying lease term and is reviewed at least annually for events or circumstances that could impair the value. Mortgage Servicing Rights: Servicing assets are recognized as separate assets when rights are acquired through purchase or sale of loans. Generally, purchased servicing rights are capitalized at the cost to acquire the rights. For sales of mortgage loans, the value of the servicing right is estimated and capitalized. Fair values are estimated based on an independent dealer analysis of discounted cash flows. Capitalized servicing rights are reported in other assets and are amortized into non-interest income in proportion to, and over the period of, the estimated future net servicing income of the underlying financial assets. Servicing assets are evaluated for impairment based upon the fair value of the rights as compared to amortized cost. Impairment is determined by stratifying rights into tranches based on predominant risk characteristics for the underlying loans, such as interest rate, balance outstanding, loan type, age and remaining term, and investor type. Impairment is recognized through a valuation allowance for an individual tranche, to the extent that fair value is less than the capitalized amount for the tranche. If the Company later determines that all or a portion of the impairment no longer exists for a particular tranche, a reduction of the allowance may be recorded as an increase to income. Servicing fee income is recorded for fees earned for servicing loans and is reflected in mortgage banking operations on the Consolidated Statements of Operations. The fees are based on a contractual percentage of the outstanding principal or a fixed amount per loan and are recorded as income when earned. The amortization of mortgage servicing rights is netted against loan servicing fee income. Bank-Owned Life Insurance (BOLI): The Banks have purchased, or acquired through mergers, life insurance policies in connection with the implementation of certain executive supplemental income, salary continuation and deferred compensation retirement plans. These policies provide protection against the adverse financial effects that could result from the death of a key employee and provide tax-exempt income to offset expenses associated with the plans. It is the Banks’ intent to hold these policies as a long-term investment; however, there may be an income tax impact if the Bank chooses to surrender certain policies. Although the lives of individual current or former management-level employees are insured, the Banks are the respective owners and sole or partial beneficiaries. Derivative Instruments: Derivatives include “off-balance-sheet” financial products, the value of which is dependent on the value of underlying financial assets, such as stock, bonds, foreign currency, or a reference rate or index. Such derivatives include “forwards,” “futures,” “options” or “swaps.” Banner Bank is a party to $8.7 million in notional amounts of interest rate swaps at December 31, 2016 . Some of these swaps serve as hedges to an equal amount of fixed rate loans which include market value prepayment penalties that mirror the provision of the specifically matched interest rate swaps. In addition, Banner Bank uses an interest rate swap program for commercial loan customers that provides the client with a variable rate loan and enters into an interest rate swap allowing them to effectively fix their loan interest rates. These customer swaps are matched with third party swaps with qualified broker/dealer or banks to offset the risk. At December 31, 2016 , Banner Bank had $307.1 million in notional amounts of these customer interest rate swaps outstanding, with

ACCOUNTING STANDARDS RECENTLY A

ACCOUNTING STANDARDS RECENTLY ADOPTED OR ISSUED	12 Months Ended
	Dec. 31, 2016
Accounting Changes and Error Corrections [Abstract]
ACCOUNTING STANDARDS RECENTLY ADOPTED OR ISSUED	ACCOUNTING STANDARDS RECENTLY ISSUED OR ADOPTED Revenue from Contracts with Customers In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers , which creates Topic 606 and supersedes Topic 605, Revenue Recognition . The core principle of Topic 606 is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In general, the new guidance requires companies to use more judgment and make more estimates than under current guidance, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. Under the terms of ASU 2015-14 the standard is effective for interim and annual periods beginning after December 15, 2017. Early application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. For financial reporting purposes, the standard allows for either full retrospective adoption, meaning the standard is applied to all of the periods presented, or modified retrospective adoption, meaning the standard is applied only to the most current period presented in the financial statements with the cumulative effect of initially applying the standard recognized at the date of initial application. The Company is currently evaluating the provisions of ASU No. 2014-09 to determine the potential impact the standard will have on the Company’s Consolidated Financial Statements. As a financial institution, the Company's largest component of revenue, interest income, is excluded from the scope this ASU. The Company is currently evaluating which if any of its sources of non-interest income will be impacted by this ASU. In April 2016, FASB issued ASU No. 2016-10, Identifying Performance Obligations and Licensing . The amendments in this ASU do not change the core principle of the guidance in Topic 606. Rather, the amendments in this ASU clarify the following two aspects of Topic 606: identifying performance obligations and the licensing implementation guidance, while retaining the related principles for those areas. The amendments in this ASU affect the guidance in ASU 2014-09, discussed above, which is not yet effective. The effective date and transition requirements for the amendments in this ASU are the same as the effective date and transition requirements in Topic 606 (Revenues from Contracts with Customers). The Company is evaluating the provisions of this ASU in conjunction with ASU No. 2014-09 to determine the potential impact Topic 606 and its amendments will have on the Company’s Consolidated Financial Statements. In May 2016, FASB issued ASU No. 2016-12, Narrow-Scope Improvements and Practical Expedients , amending ASC Topic 606 ( Revenue from Contracts with Customers ). The amendments in this ASU do not change the core principle of the guidance in Topic 606. Rather, the amendments in this ASU affect only several narrow aspects of Topic 606. The amendments in this ASU affect the guidance in ASU 2014-09, discussed above, which is not yet effective. The effective date and transition requirements for the amendments in this ASU are the same as the effective date and transition requirements in Topic 606 ( Revenues from Contracts with Customers ). The Company is evaluating the provisions of this ASU in conjunction with ASU No. 2014-09 to determine the potential impact Topic 606 and its amendments will have on the Company’s Consolidated Financial Statements. Customer's Accounting for Fees Paid in a Cloud Computing Arrangement In April 2015, FASB issued ASU No. 2015-05, Customer's Accounting for Fees Paid in a Cloud Computing Arrangement . The amendments in this ASU provide guidance to customers in cloud computing arrangements about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The amendments were effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2015 and were adopted by the Company as of January 1, 2016. This ASU did not have a material effect on the Company's Consolidated Financial Statements. Business Combinations—Simplifying the Accounting for Measurement-Period Adjustments In September 2015, FASB issued ASU No. 2015-16, Simplifying the Accounting for Measurement-Period Adjustments . The amendments in this ASU require that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period when the adjustment amounts are determined. The acquirer is required to record in the same period's financial statements the effect on earnings from changes in depreciation, amortization, or other income effects resulting from the change to provisional amounts, calculated as if the accounting had been completed at the acquisition date. The acquirer must present separately on the income statement, or disclose in the notes, the amount recorded in current-period earnings that would have been recorded in previous reporting periods if the provisional amount had been recognized at the acquisition date. The amendments in this ASU were effective for fiscal years beginning after December 15, 2015 and were adopted by the Company as of January 1, 2016. As a result of this ASU, the adjustments recorded during 2016 to the provisional amounts recorded as of December 31, 2015 related to the acquisition of Starbuck Bancshares, Inc. (Starbuck) were recorded in the current period. Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities . The amendments in this ASU require equity securities to be measured at fair value with changes in the fair value recognized through net income. The amendments allow equity investments that do not have readily determinable fair values to be remeasured at fair value under certain circumstances and require enhanced disclosures about those investments. The amendments simplify the impairment assessment of equity investments without readily determinable fair values. The amendments also eliminate the requirement to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet. The amendments in this ASU require separate presentation in other comprehensive income of the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. This amendment excludes from net income gains or losses that the entity may not realize because those financial liabilities are not usually transferred or settled at their fair values before maturity. The amendments in this ASU require separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (that is, securities or loans and receivables) on the balance sheet or in the accompanying notes to the financial statements. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Company is currently evaluating the provisions of ASU No. 2016-01 to determine the potential impact the new standard will have on the Company's Consolidated Financial Statements. Leases (Topic 842) In February 2016, FASB issued ASU No. 2016-02, Leases (Topic 842) . The amendments in this ASU require lessees to recognize the following for all leases (with the exception of short-term) at the commencement date; a lease liability, which is a lessee‘s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. The amendments in this ASU leave lessor accounting largely unchanged, although certain targeted improvements were made to align lessor accounting with the lessee accounting model. This ASU simplifies the accounting for sale and leaseback transactions primarily because lessees must recognize lease assets and lease liabilities. Lessees will no longer be provided with a source of off-balance sheet financing. The amendments in this ASU are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application is permitted upon issuance. Lessees (for capital and operating leases) and lessors (for sales-type, direct financing, and operating leases) must apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The modified retrospective approach would not require any transition accounting for leases that expired before the earliest comparative period presented. Lessees and lessors may not apply a full retrospective transition approach. The Company is currently evaluating the provisions of ASU No. 2016-02 to determine the potential impact the new standard will have on the Company's Consolidated Financial Statements. The Company leases 108 buildings and offices under non-cancelable operating leases, the majority of which will be subject to this ASU. While the Company has not quantified the impact to its balance sheet, it does expect the adoption of this ASU will result in a gross-up in its balance sheet as a result of recording a right-of-use asset and lease liability for these leases. Derivatives and Hedging (Topic 815) In March 2016, FASB issued ASU No. 2016-05, Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships . The amendments in this ASU clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815 ( Derivatives and Hedging ) does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The amendments in this ASU are effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. An entity has an option to apply the amendments in this ASU on either a prospective basis or a modified retrospective basis. Early adoption is permitted, including adoption in an interim period. At December 31, 2016, Banner had four swap relationships using hedge accounting with a total market value of $660,000. This ASU became effective for the Company on January 1, 2017 and is not expected to have a material impact on the Company’s Consolidated Financial Statements. In March 2016, FASB issued ASU No. 2016-06, Contingent Put and Call Options in Debt Instruments . The amendments in this ASU clarify the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. To determine how to account for debt instruments with embedded features, including contingent put and call options, an entity is required to assess whether the embedded derivatives must be bifurcated from the host contract and accounted for separately. Part of this assessment consists of evaluating whether the embedded derivative features are clearly and closely related to the debt host. Under existing guidance, for contingently exercisable options to be considered clearly and closely related to a debt host, they must be indexed only to interest rates or credit risk. ASU 2016-06 addresses inconsistent interpretations of whether an event that triggers an entity’s ability to exercise the embedded contingent option must be indexed to interest rates or credit risk for that option to qualify as clearly and closely related. Diversity in practice has developed because the existing four-step decision sequence in ASC 815 focuses only on whether the payoff was indexed to something other than an interest rate or credit risk. As a result, entities have been uncertain whether they should (1) determine whether the embedded features are clearly and closely related to the debt host solely on the basis of the four-step decision sequence or (2) first apply the four-step decision sequence and then also evaluate whether the event triggering the exercisability of the contingent put or call option is indexed only to an interest rate or credit risk. This ASU clarifies that in assessing whether an embedded contingent put or call option is clearly and closely related to the debt host, an entity is required to perform only the four-step decision sequence in ASC 815 as amended by this ASU. The entity does not have to separately assess whether the event that triggers its ability to exercise the contingent option is itself indexed only to interest rates or credit risk. The amendments in this ASU are effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. This ASU became effective for the Company on January 1, 2017 and is not expected to have a material impact on the Company’s Consolidated Financial Statements. Compensation—Stock Compensation (Topic 718) In March 2016, FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting . FASB issued this ASU as part of its Simplification Initiative. The areas for simplification in this ASU involve several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. Amendments in this ASU relate to the timing of when excess tax benefits are recognized, minimum statutory withholding requirements, forfeitures, and intrinsic value should be applied using a modified retrospective transition method by means of a cumulative-effect adjustment to equity as of the beginning of the period in which the guidance is adopted. Amendments related to the presentation of employee taxes paid on the statement of cash flows when an employer withholds shares to meet the minimum statutory withholding requirement should be applied retrospectively. Amendments in this ASU require recognition of excess tax benefits and tax deficiencies in the income statement and the practical expedient for estimating expected term should be applied prospectively. An entity may elect to apply the amendments in this ASU related to the presentation of excess tax benefits on the statement of cash flows using either a prospective transition method or a retrospective transition method. The amendments in this ASU are effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. This ASU became effective for the Company on January 1, 2017 and is not expected to have a material impact on the Company’s Consolidated Financial Statements. Financial Instruments—Credit Losses (Topic 326) In June 2016, FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments . Current GAAP requires an “incurred loss” methodology for recognizing credit losses that delays recognition until it is probable a loss has been incurred. The main objective of this ASU is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The amendments in this ASU replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The amendments in this ASU require a financial asset (or group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset(s) to present the net carrying value at the amount expected to be collected on the financial asset. The measurement of expected credit losses will be based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. The amendments in this ASU broaden the information that an entity must consider in developing its expected credit loss estimate for assets measured either collectively or individually. The use of forecasted information incorporates more timely information in the estimate of expected credit loss, which will be more decision useful to users of the financial statements. The amendments in this ASU will be effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company is still evaluating the effects this ASU will have on the Company’s Consolidated Financial Statements. While the Company has not quantified the impact of this ASU, it does expect changing from the current incurred loss model to an expected loss model will result in an earlier recognition of losses. Statement of Cash Flows (Topic 230) In August 2016, FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments . There is diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230 and other Topics. This ASU addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. Those eight issues are (1) debt prepayment or debt extinguishment costs, (2) settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, (3) contingent consideration payments made after a business combination, (4) proceeds from the settlement of insurance claims, (5) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies, (6) distributions received from equity method investees, (7) beneficial interests in securitization transactions, and (8) separately identifiable cash flows and application of the predominance principle. Current GAAP either is unclear or does not include specific guidance on these eight cash flow classification issues. These amendments provide guidance for each of the eight issues, thereby reducing current and potential future diversity in practice. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The Company elected to early adopt in the fourth quarter of 2016. This ASU did not have a material impact on the Company's Consolidated Financial Statements. Intangibles—Goodwill and Other (Topic 350) In January 2017, FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment . The amendments in this ASU are intended to reduce the cost and complexity of the goodwill impairment test by eliminating Step 2 from the that impairment test. The amendments modify the concept of impairment from the condition that exists when the carrying amount of goodwill exceeds its implied fair value to the condition that exists when the carrying amount of a reporting unit exceeds its fair value. Under the amendments in this ASU, an entity will perform its annual, or interim, goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount. An impairment charge should be recognized for the amount which the carrying amount exceeds the reporting unit's fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The amendments in this ASU are effective for the Company's annual or any interim goodwill impairment test in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company is early adopting these amendments in 2017 and does not expect a material impact on the Company's Consolidated Financial Statements.

BUSINESS COMBINATIONS BUSINESS

BUSINESS COMBINATIONS BUSINESS COMBINATIONS	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
BUSINESS COMBINATIONS	BUSINESS COMBINATIONS Acquisition of Starbuck Bancshares, Inc. Effective as of the close of business on October 1, 2015 , the Company acquired Starbuck Bancshares, Inc. (Starbuck) and its subsidiary, AmericanWest Bank (AmericanWest), a Washington state chartered commercial bank headquartered in Spokane, Washington with 98 branches serving markets in Washington, Oregon, Idaho, California and Utah. On that date, Starbuck merged with and into Banner and AmericanWest merged with and into Banner Bank. The merged banks are operating as Banner Bank. Pursuant to the previously announced terms of the merger, the equity holders of Starbuck received an aggregate of $130.0 million in cash and 13.23 million shares of Banner voting common stock and nonvoting common stock. The acquisition provided $4.46 billion in assets, $3.64 billion in deposits and $3.00 billion in loans to Banner. At the closing date, the combined company had approximately $9.9 billion in assets and 203 branches. The application of the acquisition method of accounting resulted in recognition of a CDI asset of $33.5 million and goodwill of $222.9 million . The acquired CDI has been determined to have a useful life of approximately ten years and will be amortized on an accelerated basis. Goodwill is not amortized but will be evaluated for impairment on an annual basis or more often if circumstances dictate to determine if the carrying value remains appropriate. Goodwill will not be deductible for income tax purposes as the acquisition is accounted for as a tax-free exchange for tax purposes. The following table presents a summary of the consideration paid and the estimated fair values as of the acquisition date for each major class of assets acquired and liabilities assumed (in thousands): Starbuck October 1, 2015 Consideration to Starbuck equityholders: Cash paid $ 130,000 Fair value of common shares issued 630,674 Total consideration 760,674 Fair value of assets acquired: Cash and cash equivalents $ 95,821 Securities 1,037,238 Loans receivable (contractual amount of $3.04 billion) 2,999,130 REO, held for sale 6,105 Property and equipment 66,728 CDI 33,500 Deferred tax asset 108,454 Other assets 113,009 Total assets acquired 4,459,985 Fair value of liabilities assumed: Deposits 3,638,596 FHLB advances 221,442 Junior subordinated debentures 5,806 Other liabilities 56,359 Total liabilities assumed 3,922,203 Net assets acquired 537,782 Goodwill $ 222,892 Acquired goodwill represents the premium the Company paid over the fair value of the net tangible and intangible assets acquired. The acquisition complements the Company's growth strategy, including expanding our geographic footprint in markets throughout the Northwest, Utah and California. The Company paid this premium for a number of reasons, including growing the Company's customer base, acquiring assembled workforces, and expanding its presence in new markets. See Note 17, Goodwill, Other Intangible Assets and Mortgage Servicing Rights for the accounting for goodwill and other intangible assets. As of October 1, 2015, the unpaid principal balance on purchased non-credit-impaired loans was $2.95 billion . The fair value of the purchased non-credit-impaired loans was $2.94 billion , resulting in a discount of $17.7 million recorded on these loans. The principal cash flows not expected to be collected on these loans was estimated to be $44.1 million . This discount is being accreted into income over the life of the loans on an effective yield basis. The following table presents the acquired PCI loans as of the acquisition date (in thousands): Starbuck October 1, 2015 Acquired PCI loans: Contractually required principal and interest payments $ 98,746 Nonaccretable difference (26,162 ) Cash flows expected to be collected 72,584 Accretable yield (11,071 ) Fair value of PCI loans $ 61,513 The following table presents certain unaudited pro forma information for illustrative purposes only, for the year ended December 31, 2015 as if Starbuck had been acquired on January 1, 2014. This unaudited estimated pro forma financial information combines the historical results of Starbuck with the Company’s consolidated historical results. Pro forma adjustments include accretion of loan discount, accretion of investment premiums, amortization of deposit premium, amortization of CDI, reversal of acquisition expense, and reversal of historical recorded amounts for similar items, with all adjustments tax effected. The pro forma information is not indicative of what would have occurred had the acquisition actually occurred on January 1, 2014. In particular, no adjustments have been made to eliminate the impact of other-than-temporary impairment losses and losses recognized on the sale of securities that may not have been necessary had the investment securities been recorded at fair value as of January 1, 2014. The unaudited pro forma information does not consider any changes to the provision for credit losses resulting from recording loan assets at fair value. Additionally, Banner expects to achieve further operating cost savings and other business synergies, including revenue growth, as a result of the acquisition which are not reflected in the pro forma amounts that follow. As a result, actual amounts would have differed from the unaudited pro forma information presented (in thousands except per share amounts): Pro Forma Year Ended December 31 2015 Total revenues (net interest income plus non-interest income) $ 455,427 Net income $ 86,255 Earnings per share - basic $ 2.56 Earnings per share - diluted $ 2.55 The operating results of the Company include the operating results produced by the acquired assets and assumed liabilities of Starbuck since October 2, 2015. Disclosure of the amount of Starbuck's revenue and net income (excluding integration costs) included in the Company’s Consolidated Statements of Operations is impracticable due to the integration of the operations, systems and accounting for this acquisition occurring in different stages. Acquisition of Siuslaw Financial Group, Inc. Effective as of the close of business on March 6, 2015 , the Company completed the purchase of Siuslaw Financial Group, Inc. (Siuslaw), the holding company of Siuslaw Bank, an Oregon state chartered commercial bank. Siuslaw merged with and into the Company and, immediately thereafter, Siuslaw Bank merged with and into Banner Bank. Siuslaw shareholders received 0.32231 shares of the Company's common stock and $1.41622 in cash in exchange for each share of Siuslaw common stock. The acquisition provided $369.8 million in assets, $316.4 million in deposits and $247.1 million in loans. The application of the acquisition method of accounting resulted in recognition of a CDI asset of $3.9 million and goodwill of $21.7 million . The acquired CDI has been determined to have a useful life of approximately eight years and will be amortized on an accelerated basis. Goodwill is not amortized but will be evaluated for impairment on an annual basis or more often if circumstances dictate to determine if the carrying value remains appropriate. The goodwill is not deductible for income tax purposes since the acquisition is accounted for as a tax-free exchange for tax purposes. The following table presents a summary of the consideration paid and the estimated fair values as of the acquisition date for each major class of assets acquired and liabilities assumed (in thousands): Siuslaw March 6, 2015 Consideration to Siuslaw shareholders: Cash paid $ 5,806 Fair value of common shares issued 58,100 Total consideration 63,906 Fair value of assets acquired: Cash and cash equivalents $ 84,405 Securities—available-for-sale 12,865 Loans receivable (contractual amount of $252.2 million) 247,098 REO, held for sale 2,525 Property and equipment 8,127 CDI 3,895 Other assets 10,848 Total assets acquired 369,763 Fair value of liabilities assumed: Deposits 316,406 Junior subordinated debentures 5,959 Other liabilities 5,183 Total liabilities assumed 327,548 Net assets acquired $ 42,215 Goodwill 21,691 Acquired goodwill represents the premium the Company paid over the fair value of the net tangible and intangible assets acquired. The acquisition complements the Company's growth strategy, including expanding our geographic footprint in markets throughout the Northwest. The Company paid this premium for a number of reasons, including growing the Company's customer base, acquiring assembled workforces, and expanding its presence in new markets. See Note 17, Goodwill, Other Intangible Assets and Mortgage Servicing Rights for the accounting for goodwill and other intangible assets. As of March 6, 2015, the unpaid principal balance on purchased non-credit-impaired loans was $244.2 million . The fair value of the purchased non-credit-impaired loans was $241.4 million , resulting in a discount of $2.8 million recorded on these loans. This discount is being accreted into income over the life of the loans on an effective yield basis. The following table presents the acquired PCI loans as of the acquisition date (in thousands): Siuslaw March 6, 2015 Acquired PCI loans: Contractually required principal and interest payments $ 11,134 Nonaccretable difference (3,238 ) Cash flows expected to be collected 7,896 Accretable yield (2,239 ) Fair value of PCI loans $ 5,657 The following table presents certain unaudited pro forma information for illustrative purposes only, for the year ended December 31, 2015 as if Siuslaw had been acquired on January 1, 2014. This unaudited estimated pro forma financial information combines the historical results of Siuslaw with the Company’s consolidated historical results. Pro forma adjustments include, accretion of loan discount, accretion of investment premiums, amortization of deposit premium, amortization of CDI, reversal of acquisition expense, and reversal of historical recorded amounts for similar items, with all adjustments tax effected. The pro forma information is not indicative of what would have occurred had the acquisition actually occurred on January 1, 2014. In particular, no adjustments have been made to eliminate the impact of other-than-temporary impairment losses and losses recognized on the sale of securities that may not have been necessary had the investment securities been recorded at fair value as of January 1, 2014. The unaudited pro forma information does not consider any changes to the provision for credit losses resulting from recording loan assets at fair value. Additionally, Banner expects to achieve further operating cost savings and other business synergies, including revenue growth, as a result of the acquisition which are not reflected in the pro forma amounts that follow. As a result, actual amounts would have differed from the unaudited pro forma information presented (in thousands except per share amounts): Pro Forma Year Ended December 31 2015 Total revenues (net interest income plus non-interest income) $ 308,153 Net income $ 44,484 Earnings per share - basic $ 1.85 Earnings per share - diluted $ 1.85 The operating results of the Company include the operating results produced by the acquired assets and assumed liabilities of Siuslaw for the period since March 7, 2015. Disclosure of the amount of Siuslaw’s revenue and net income (excluding integration costs) included in the Company’s Consolidated Statements of Operations is impracticable due to the integration of the operations and accounting for this acquisition. Acquisition-Related Costs The following tables present the key components of acquisition-related costs in connection with the purchase of six Oregon branches in 2014 (the Branch purchase), the acquisition of Siuslaw and the acquisition of Starbuck, including AmericanWest, for the years ended December 31, 2016 , 2015 and 2014 (in thousands): Years Ended December 31 2016 2015 2014 Acquisition-related costs recognized in non-interest expense: Personnel severance/retention fees $ 1,384 $ 6,577 $ — Non-capitalized equipment and repairs 2,590 1,031 105 Client communications 1,158 527 327 Information/computer data services 2,490 2,875 334 Payment and processing expenses 197 28 185 Professional services 2,230 11,169 2,953 Miscellaneous 1,684 3,903 421 $ 11,733 $ 26,110 $ 4,325 The Branch purchase $ — $ — $ 1,784 Siuslaw 95 2,000 748 Starbuck 11,638 24,110 1,793 $ 11,733 $ 26,110 $ 4,325

SECURITIES

SECURITIES	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
SECURITIES	SECURITIES The amortized cost, gross unrealized losses and gains and estimated fair value of securities at December 31, 2016 and 2015 are summarized as follows (in thousands): December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Trading: U.S. Government and agency obligations $ 1,230 $ 1,326 Municipal bonds 331 335 Corporate bonds 26,959 21,143 Mortgage-backed or related securities 1,620 1,641 Equity securities 14 123 $ 30,154 $ 24,568 Available-for-Sale: U.S. Government and agency obligations $ 57,288 $ 146 $ (456 ) $ 56,978 Municipal bonds 110,487 455 (1,089 ) 109,853 Corporate bonds 10,255 77 (49 ) 10,283 Mortgage-backed or related securities 598,899 2,064 (6,251 ) 594,712 Asset-backed securities 29,319 — (326 ) 28,993 Equity securities 88 10 — 98 $ 806,336 $ 2,752 $ (8,171 ) $ 800,917 Held-to-Maturity: U.S. Government and agency obligations $ 1,065 $ — $ (18 ) $ 1,047 Municipal bonds: 196,989 4,173 (1,272 ) 199,890 Corporate bonds 3,876 — — 3,876 Mortgage-backed or related securities 65,943 309 (537 ) 65,715 $ 267,873 $ 4,482 $ (1,827 ) $ 270,528 December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Trading: U.S. Government and agency obligations $ 1,230 $ 1,368 Municipal bonds 332 341 Corporate bonds 25,063 18,699 Mortgage-backed or related securities 12,705 13,663 Equity securities 14 63 $ 39,344 $ 34,134 Available-for-Sale: U.S. Government and agency obligations $ 30,211 $ 213 $ (193 ) $ 30,231 Municipal bonds 142,898 853 (432 ) 143,319 Corporate bonds 15,937 56 (12 ) 15,981 Mortgage-backed or related securities 919,318 4,056 (5,115 ) 918,259 Asset-backed securities 31,288 — (603 ) 30,685 Equity securities 88 10 — 98 $ 1,139,740 $ 5,188 $ (6,355 ) $ 1,138,573 Held-to-Maturity: U.S. Government and agency obligations $ 1,106 $ 5 $ — $ 1,111 Municipal bonds: 162,778 6,219 (191 ) 168,806 Corporate bonds 4,273 — — 4,273 Mortgage-backed or related securities 52,509 253 (325 ) 52,437 $ 220,666 $ 6,477 $ (516 ) $ 226,627 At December 31, 2016 and 2015 , the gross unrealized losses and the fair value for securities available-for-sale and held-to-maturity aggregated by the length of time that individual securities have been in a continuous unrealized loss position was as follows (in thousands): December 31, 2016 Less Than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Available-for-Sale: U.S. Government and agency obligations $ 39,043 $ (442 ) $ 1,012 $ (14 ) $ 40,055 $ (456 ) Municipal bonds 60,765 (1,087 ) 556 (2 ) 61,321 (1,089 ) Corporate bonds 5,206 (49 ) — — 5,206 (49 ) Mortgage-backed or related securities 403,431 (5,604 ) 47,467 (647 ) 450,898 (6,251 ) Asset-backed securities 9,928 (101 ) 19,064 (225 ) 28,992 (326 ) $ 518,373 $ (7,283 ) $ 68,099 $ (888 ) $ 586,472 $ (8,171 ) Held-to-Maturity: U.S. Government and agency obligations $ 1,047 $ (18 ) $ — $ — $ 1,047 $ (18 ) Municipal bonds $ 64,802 $ (1,267 ) $ 204 $ (5 ) $ 65,006 $ (1,272 ) Mortgage-backed or related securities 42,245 (537 ) — — 42,245 (537 ) $ 108,094 $ (1,822 ) $ 204 $ (5 ) $ 108,298 $ (1,827 ) December 31, 2015 Less Than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Available-for-Sale: U.S. Government and agency obligations $ 8,707 $ (97 ) $ 10,489 $ (96 ) $ 19,196 $ (193 ) Municipal bonds 69,848 (426 ) 905 (6 ) 70,753 (432 ) Corporate bonds 5,153 (12 ) — — 5,153 (12 ) Mortgage-backed or related securities 533,143 (4,380 ) 68,562 (735 ) 601,705 (5,115 ) Asset-backed securities 20,893 (355 ) 9,792 (248 ) 30,685 (603 ) $ 637,744 $ (5,270 ) $ 89,748 $ (1,085 ) $ 727,492 $ (6,355 ) Held-to-Maturity: Municipal bonds $ 28,545 $ (188 ) $ 254 $ (3 ) $ 28,799 $ (191 ) Mortgage-backed or related securities 34,493 (323 ) 255 (2 ) 34,748 (325 ) $ 63,038 $ (511 ) $ 509 $ (5 ) $ 63,547 $ (516 ) At December 31, 2016 , there were 243 securities—available-for-sale with unrealized losses, compared to 242 at December 31, 2015 and 94 at December 31, 2014 . At December 31, 2016 , there were 73 securities—held-to-maturity with unrealized losses, compared to 32 at December 31, 2015 and 25 at December 31, 2014 . Management does not believe that any individual unrealized loss as of December 31, 2016 , 2015 or 2014 represented OTTI. The decline in fair market value of these securities was generally due to changes in interest rates. Sales of securities—trading totaled $7.8 million with a resulting net gain of $530,000 for the year ended December 31, 2016 and totaled $4.4 million with a resulting net loss of $690,000 for the year ended December 31, 2015 . Sales of securities—trading for the year ended December 31, 2014 totaled $2.4 million with a resulting net gain of $1,000 . The Company did no t recognize any OTTI charges or recoveries on securities—trading during the years ended December 31, 2016 , 2015 or 2014. There were no securities—trading in a nonaccrual status at December 31, 2016 and 2015 . Net unrealized holding losses of $376,000 were recognized in 2016 and $2.0 million in 2015 . Sales of securities—available-for-sale totaled $369.8 million with a resulting net gain of $311,000 for the year ended December 31, 2016 . Sales of securities—available-for-sale totaled $232.6 million with a resulting net gain of $126,000 for the year ended December 31, 2015 . Sales of securities—available-for-sale totaled $56.3 million with a resulting net gain of $41,000 for the year ended December 31, 2014 . There were no securities—available-for-sale in a nonaccrual status at December 31, 2016 and 2015 . There were no sales of securities—held-to-maturity during the years ended December 31, 2016 , 2015 or 2014 . There were no securities—held-to-maturity in a nonaccrual status at December 31, 2016 and 2015 . The amortized cost and estimated fair value of securities at December 31, 2016 , by contractual maturity, are shown below (in thousands). Expected maturities will differ from contractual maturities because some securities may be called or prepaid with or without call or prepayment penalties. December 31, 2016 Trading Available-for-Sale Held-to-Maturity Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Maturing in one year or less $ 1,751 $ 1,775 $ 13,077 $ 13,063 $ 1,962 $ 1,975 Maturing after one year through five years 230 231 120,405 120,126 18,988 19,000 Maturing after five years through ten years 1,200 1,296 176,010 173,720 113,587 114,336 Maturing after ten years through twenty years — — 188,557 187,940 88,546 91,098 Maturing after twenty years 26,959 21,143 308,199 305,970 44,790 44,119 30,140 24,445 806,248 800,819 267,873 270,528 Equity securities 14 123 88 98 — — $ 30,154 $ 24,568 $ 806,336 $ 800,917 $ 267,873 $ 270,528 The following table presents, as of December 31, 2016 , investment securities which were pledged to secure borrowings, public deposits or other obligations as permitted or required by law (in thousands): Carrying Value Amortized Cost Fair Value Purpose or beneficiary: State and local governments public deposits $ 203,510 $ 203,474 $ 207,013 Interest rate swap counterparties 24,393 24,447 24,287 Repurchase transaction accounts 114,949 115,650 114,864 Other 1,778 1,782 1,778 Total pledged securities $ 344,630 $ 345,353 $ 347,942

LOANS RECEIVABLE AND THE ALLOWA

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES	LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES Loans receivable at December 31, 2016 and 2015 are summarized as follows (dollars in thousands): December 31, 2016 December 31, 2015 Amount Percent of Total Amount Percent of Total Commercial real estate: Owner-occupied $ 1,352,999 18.1 % $ 1,327,807 18.2 % Investment properties 1,986,336 26.7 1,765,353 24.1 Multifamily real estate 248,150 3.3 472,976 6.5 Commercial construction 124,068 1.7 72,103 1.0 Multifamily construction 124,126 1.7 63,846 0.9 One- to four-family construction 375,704 5.0 278,469 3.8 Land and land development: Residential 170,004 2.3 126,773 1.7 Commercial 29,184 0.4 33,179 0.5 Commercial business 1,207,879 16.2 1,207,944 16.5 Agricultural business, including secured by farmland 369,156 5.0 376,531 5.1 One- to four-family residential 813,077 10.9 952,633 13.0 Consumer: Consumer secured by one- to four-family 493,211 6.6 478,420 6.5 Consumer—other 157,254 2.1 158,470 2.2 Total loans outstanding 7,451,148 100.0 % 7,314,504 100.0 % Less allowance for loan losses (85,997 ) (78,008 ) Net loans $ 7,365,151 $ 7,236,496 Loan amounts are net of unearned loan fees in excess of unamortized costs of $5.8 million at December 31, 2016 and $5.5 million at December 31, 2015 . Net loans include net discounts on acquired loans of $31.1 million and $43.7 million as of December 31, 2016 and 2015 , respectively. The Company’s loans to directors, executive officers and related entities are on substantially the same terms and underwriting as those prevailing at the time for comparable transactions with unrelated persons and do not involve more than normal risk of collectability. Such loans had balances of $4.3 million and $7.9 million for the years ended December 31, 2016 and 2015 , respectively. Purchased credit-impaired loans: The outstanding contractual unpaid principal balance of PCI loans, excluding acquisition accounting adjustments, were $48.4 million at December 31, 2016 and $83.4 million at December 31, 2015. The carrying balance of PCI loans were $32.3 million at December 31, 2016 and $58.6 million at December 31, 2015 . The following table presents the changes in the accretable yield for PCI loans for the years ended December 31, 2016 and 2015 (in thousands): Years Ended December 31 2016 2015 Balance, beginning of period $ 10,375 $ — Additions — 13,310 Accretion to interest income (9,333 ) (2,202 ) Disposals and other (1,018 ) (1,238 ) Reclassifications from non-accretable difference 8,693 505 Balance, end of period $ 8,717 $ 10,375 As of December 31, 2016 and December 31, 2015, the non-accretable difference between the contractually required payments and cash flows expected to be collected was $15.7 million and $29.5 million , respectively. Impaired Loans and the Allowance for Loan Losses: A loan is considered impaired when, based on current information and circumstances, the Company determines it is probable that it will be unable to collect all amounts due according to the contractual terms of the loan agreement, including scheduled interest payments. Factors involved in determining impairment include, but are not limited to, the financial condition of the borrower, the value of the underlying collateral and the current status of the economy. Impaired loans are comprised of loans on nonaccrual, TDRs, and loans that are 90 days or more past due, but are still on accrual. Purchased credit-impaired loans are considered performing within the scope of the PCI accounting guidance and are not included in the impaired loan tables. The following tables provide additional information on impaired loans, excluding PCI loans, with and without specific allowance reserves at December 31, 2016 and 2015 . Recorded investment includes the unpaid principal balance or the carrying amount of loans less charge-offs and net deferred loan fees (in thousands): December 31, 2016 Unpaid Principal Balance Recorded Investment Related Allowance Without Allowance (1) With Allowance (2) Commercial real estate: Owner-occupied $ 3,786 $ 1,778 $ 1,798 $ 175 Investment properties 9,916 4,015 5,854 580 Multifamily real estate 508 — 496 81 One- to four-family construction 1,180 — 1,180 156 Land and land development: Residential 3,012 750 1,106 219 Commercial 1,608 998 — — Commercial business 3,753 2,294 1,431 154 Agricultural business/farmland 6,438 5,886 468 35 One- to four-family residential 11,439 90 11,085 655 Consumer: Consumer secured by one- to four-family 1,904 — 1,865 179 Consumer—other 391 4 388 29 $ 43,935 $ 15,815 $ 25,671 $ 2,263 December 31, 2015 Unpaid Principal Balance Recorded Investment Related Allowance Without Allowance (1) With Allowance (2) Commercial real estate: Owner-occupied $ 1,465 $ — $ 1,416 $ 70 Investment properties 8,740 2,503 5,846 602 Multifamily real estate 359 — 357 71 Commercial construction 1,141 1,069 — — One- to four-family construction 1,741 — 1,741 161 Land and land development: Residential 3,540 750 1,634 444 Commercial 1,628 1,027 — — Commercial business 2,266 538 1,184 150 Agricultural business/farmland 1,309 544 697 43 One- to four-family residential 17,897 2,206 14,418 736 Consumer: Consumer secured by one- to four-family 776 — 716 23 Consumer—other 433 — 351 7 $ 41,295 $ 8,637 $ 28,360 $ 2,307 (1) Loans without an allowance reserve have been individually evaluated for impairment and that evaluation concluded that no reserve was needed. (2) Includes general reserves for loans evaluated in pools of homogeneous loans and loans with a specific reserve allowance. Loans with a specific allowance reserve have been individually evaluated for impairment using either a discounted cash flow analysis or, for collateral dependent loans, current appraisals less costs to sell to establish realizable value. The following table summarizes our average recorded investment and interest income recognized on impaired loans by loan class for the years ended December 31, 2016 , 2015 and 2014 (in thousands): Year Ended December 31, 2016 Year Ended December 31, 2015 Year Ended December 31, 2014 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial real estate: Owner-occupied $ 2,721 $ 2 $ 1,467 $ 9 $ 1,841 $ 12 Investment properties 18,529 242 8,003 303 6,145 315 Multifamily real estate 513 21 362 18 795 45 One- to four-family construction 1,158 75 1,463 114 2,655 118 Land and land development: Residential 1,948 85 2,406 49 2,872 89 Commercial 1,003 — 931 — — — Commercial business 4,290 37 1,667 35 1,328 41 Agricultural business/farmland 5,004 119 1,143 19 1,866 — One- to four-family residential 11,976 441 17,770 630 26,093 870 Consumer: Consumer secured by one- to four-family 1,778 17 736 11 1,248 19 Consumer—other 615 17 392 18 597 19 $ 49,535 $ 1,056 $ 36,340 $ 1,206 $ 45,440 $ 1,528 The following table presents TDRs by accrual and nonaccrual status at December 31, 2016 and 2015 (in thousands): December 31, 2016 December 31, 2015 Accrual Status Nonaccrual Status Total TDRs Accrual Nonaccrual Total Commercial real estate: Owner-occupied $ 203 $ 96 $ 299 $ 181 $ 104 $ 285 Investment properties 4,304 — 4,304 5,834 13 5,847 Multifamily real estate 349 — 349 357 — 357 One- to four-family construction 1,180 — 1,180 1,741 — 1,741 Land and land development: Residential 1,106 — 1,106 1,151 483 1,634 Commercial business 653 — 653 624 — 624 Agricultural business/farmland 3,125 79 3,204 545 277 822 One- to four-family residential 7,678 843 8,521 11,025 1,428 12,453 Consumer: Consumer secured by one- to four-family 143 6 149 147 14 161 Consumer—other 166 — 166 172 — 172 $ 18,907 $ 1,024 $ 19,931 $ 21,777 $ 2,319 $ 24,096 As of December 31, 2016 and 2015 , the Company had commitments to advance funds up to an additional amount of $127,000 and $237,000 , respectively, related to TDRs. The following table presents new TDRs that occurred during the years ended December 31, 2016 and 2015 (dollars in thousands): Year Ended December 31, 2016 Year Ended December 31, 2015 Number of Contracts Pre-modification Outstanding Recorded Investment Post-modification Outstanding Recorded Investment Number of Pre-modification Outstanding Recorded Investment Post-modification Outstanding Recorded Investment Recorded Investment (1) (2) Commercial real estate: Owner-occupied 1 $ 194 $ 194 — $ — $ — Land and land development: Residential — — — 2 1,302 483 Agricultural business/farmland — — — 3 822 822 One- to four-family residential 1 78 78 2 431 431 2 $ 272 $ 272 7 $ 2,555 $ 1,736 (1) Since most loans were already considered classified and/or on non-accrual status prior to restructuring, the modifications did not have a material effect on the Company’s determination of the allowance for loan losses. (2) The majority of these modifications do not fit into one separate type, such as rate, term, amount, interest-only or payment, but instead are a combination of multiple types of modifications; therefore, they are disclosed in aggregate. The following table presents TDRs which incurred a payment default within the year ended December 31, 2015 for which the payment default occurred within twelve months of the restructure date. There were no TDRs that incurred a payment default in the year ended December 31, 2016. A default on a restructured loan results in a transfer to nonaccrual status, a charge-off or a combination of both (dollars in thousands): December 31, 2015 Number of Loans Amount Agricultural business/farmland 2 $ 277 One- to four-family residential 1 387 Total 3 $ 664 Credit Quality Indicators : To appropriately and effectively manage the ongoing credit quality of the Company’s loan portfolio, management has implemented a risk-rating or loan grading system for its loans. The system is a tool to evaluate portfolio asset quality throughout each applicable loan’s life as an asset of the Company. Generally, loans and leases are risk rated on an aggregate borrower/relationship basis with individual loans sharing similar ratings. There are some instances when specific situations relating to individual loans will provide the basis for different risk ratings within the aggregate relationship. Loans are graded on a scale of 1 to 9. A description of the general characteristics of these categories is shown below: Overall Risk Rating Definitions : Risk-ratings contain both qualitative and quantitative measurements and take into account the financial strength of a borrower and the structure of the loan or lease. Consequently, the definitions are to be applied in the context of each lending transaction and judgment must also be used to determine the appropriate risk rating, as it is not unusual for a loan or lease to exhibit characteristics of more than one risk-rating category. Consideration for the final rating is centered in the borrower’s ability to repay, in a timely fashion, both principal and interest. There were no material changes in the risk-rating or loan grading system in 2016 . Risk Rating 1: Exceptional A credit supported by exceptional financial strength, stability, and liquidity. The risk rating of 1 is reserved for the Company’s top quality loans, generally reserved for investment grade credits underwritten to the standards of institutional credit providers. Risk Rating 2: Excellent A credit supported by excellent financial strength, stability and liquidity. The risk rating of 2 is reserved for very strong and highly stable customers with ready access to alternative financing sources. Risk Rating 3: Strong A credit supported by good overall financial strength and stability. Collateral margins are strong, cash flow is stable although susceptible to cyclical market changes. Risk Rating 4: Acceptable A credit supported by the borrower’s adequate financial strength and stability. Assets and cash flow are reasonably sound and provide for orderly debt reduction. Access to alternative financing sources will be more difficult to obtain. Risk Rating 5: Watch A credit with the characteristics of an acceptable credit but one which requires more than the normal level of supervision and warrants formal quarterly management reporting. Credits in this category are not yet criticized or classified, but due to adverse events or aspects of underwriting require closer than normal supervision. Generally, credits should be watch credits in most cases for six months or less as the impact of stress factors are analyzed. Risk Rating 6: Special Mention A credit with potential weaknesses that deserves management’s close attention is risk rated a 6. If left uncorrected, these potential weaknesses will result in deterioration in the capacity to repay debt. A key distinction between Special Mention and Substandard is that in a Special Mention credit, there are identified weaknesses that pose potential risk(s) to the repayment sources, versus well defined weaknesses that pose risk(s) to the repayment sources. Assets in this category are expected to be in this category no more than 9-12 months as the potential weaknesses in the credit are resolved. Risk Rating 7: Substandard A credit with well defined weaknesses that jeopardize the ability to repay in full is risk rated a 7. These credits are inadequately protected by either the sound net worth and payment capacity of the borrower or the value of pledged collateral. These are credits with a distinct possibility of loss. Loans headed for foreclosure and/or legal action due to deterioration are rated 7 or worse. Risk Rating 8: Doubtful A credit with an extremely high probability of loss is risk rated 8. These credits have all the same critical weaknesses that are found in a substandard loan; however, the weaknesses are elevated to the point that based upon current information, collection or liquidation in full is improbable. While some loss on doubtful credits is expected, pending events may strengthen a credit making the amount and timing of any loss indeterminate. In these situations taking the loss is inappropriate until it is clear that the pending event has failed to strengthen the credit and improve the capacity to repay debt. Risk Rating 9: Loss A credit that is considered to be currently uncollectible or of such little value that it is no longer a viable Bank asset is risk rated 9. Losses are taken in the accounting period in which the credit is determined to be uncollectible. Taking a loss does not mean that a credit has absolutely no recovery or salvage value but, rather, it is not practical or desirable to defer writing off the credit, even though partial recovery may occur in the future. The following tables show Banner’s portfolio of risk-rated loans and non-risk-rated loans by grade or other characteristic as of December 31, 2016 and 2015 (in thousands): December 31, 2016 By class: Pass (Risk Ratings 1-5) (1) Special Substandard Doubtful Loss Total Loans Commercial real estate: Owner-occupied $ 1,313,142 $ 14,394 $ 25,463 $ — $ — $ 1,352,999 Investment properties 1,948,822 23,846 13,668 — — 1,986,336 Multifamily real estate 247,258 — 892 — — 248,150 Commercial construction 124,068 — — — — 124,068 Multifamily construction 124,126 — — — — 124,126 One- to four-family construction 371,636 — 4,068 — — 375,704 Land and land development: Residential 167,764 — 2,240 — — 170,004 Commercial 25,090 — 4,094 — — 29,184 Commercial business 1,148,585 35,036 24,258 — — 1,207,879 Agricultural business, including secured by farmland 356,656 3,335 9,165 — — 369,156 One- to four-family residential 807,837 967 4,273 — — 813,077 Consumer: Consumer secured by one- to four-family 490,877 5 2,327 2 — 493,211 Consumer—other 156,547 108 594 5 — 157,254 Total $ 7,282,408 $ 77,691 $ 91,042 $ 7 $ — $ 7,451,148 December 31, 2015 By class: Pass (Risk Ratings 1-5) (1) Special Substandard Doubtful Loss Total Loans Commercial real estate: Owner-occupied $ 1,281,561 $ 19,400 $ 26,846 $ — $ — $ 1,327,807 Investment properties 1,740,720 11,528 13,105 — — 1,765,353 Multifamily real estate 468,467 138 4,371 — — 472,976 Commercial construction 72,103 — — — — 72,103 Multifamily construction 63,846 — — — — 63,846 One- to four-family construction 275,154 — 3,315 — — 278,469 Land and land development: Residential 121,536 76 5,161 — — 126,773 Commercial 25,786 2,310 5,083 — — 33,179 Commercial business 1,167,933 25,286 14,725 — — 1,207,944 Agricultural business, including secured by farmland 354,760 17,526 4,245 — — 376,531 One- to four-family residential 943,098 1,346 8,189 — — 952,633 Consumer: Consumer secured by one- to four-family 476,448 — 1,967 5 — 478,420 Consumer—other 157,286 22 1,157 5 — 158,470 Total $ 7,148,698 $ 77,632 $ 88,164 $ 10 $ — $ 7,314,504 (1) The Pass category includes some performing loans that are part of homogenous pools which are not individually risk-rated. This includes all consumer loans, all one- to four-family residential loans and, as of December 31, 2016 and 2015 , in the commercial business category, $225.0 million and $150.0 million , respectively, of credit-scored small business loans. As loans in these homogeneous pools become non-accrual, they are individually risk-rated. (2) Non-performing loans include non-accrual loans and loans past due greater than 90 days but still on accrual status. The following tables provide additional detail on the age analysis of Banner’s past due loans as of December 31, 2016 and 2015 (in thousands): December 31, 2016 30 – 59 Days Past Due 60 – 89 Days Past Due 90 Days or More Past Due Total Past Due Purchased Credit-Impaired Current Total Loans Loans 90 Days or More Past Due and Accruing Non-accrual Commercial real estate: Owner-occupied $ 1,938 $ — $ 2,538 $ 4,476 $ 13,281 $ 1,335,242 $ 1,352,999 $ — $ 3,373 Investment properties 117 — 5,447 5,564 10,168 1,970,604 1,986,336 701 4,864 Multifamily real estate — — 147 147 139 247,864 248,150 147 — Commercial construction — — — — — 124,068 124,068 — — Multifamily construction — — — — — 124,126 124,126 — — One- to four-family construction — — — — 862 374,842 375,704 — — Land and land development: Residential 48 — 750 798 — 169,206 170,004 — 750 Commercial — — 998 998 3,016 25,170 29,184 — 998 Commercial business 2,314 647 1,591 4,552 3,821 1,199,506 1,207,879 — 3,074 Agricultural business/farmland 360 1,244 2,768 4,372 684 364,100 369,156 — 3,229 One- to four-family residential 1,793 249 2,110 4,152 274 808,651 813,077 1,233 2,263 Consumer: Consumer secured by one- to four-family 932 160 986 2,078 18 491,115 493,211 61 1,660 Consumer—other 1,421 154 147 1,722 59 155,473 157,254 11 215 Total $ 8,923 $ 2,454 $ 17,482 $ 28,859 $ 32,322 $ 7,389,967 $ 7,451,148 $ 2,153 $ 20,426 December 31, 2015 30–59 Days Past Due 60–89 Days Past Due 90 Days or More Past Due Total Past Due Purchased Credit-Impaired Current Total Loans Loans 90 Days or More Past Due and Accruing Non-accrual Commercial real estate: Owner-occupied $ 3,981 $ 139 $ 885 $ 5,005 $ 24,261 $ 1,298,541 $ 1,327,807 $ — $ 1,235 Investment properties 1,763 132 2,503 4,398 16,724 1,744,231 1,765,353 — 2,516 Multifamily real estate 4 — — 4 1,994 470,978 472,976 — — Commercial construction — — — — — 72,103 72,103 — — Multifamily construction 771 13 — 784 — 63,062 63,846 — — One- to four-family construction 2,466 220 — 2,686 905 274,878 278,469 — 1,233 Land and land development: Residential — — 747 747 77 125,949 126,773 — 1,027 Commercial — 96 — 96 4,668 28,415 33,179 — — Commercial business 1,844 174 1,024 3,042 7,302 1,197,600 1,207,944 8 2,159 Agricultural business/farmland 323 729 278 1,330 1,529 373,672 376,531 — 697 One- to four-family residential 620 873 3,811 5,304 1,066 946,263 952,633 899 4,700 Consumer: Consumer secured by one- to four-family 465 60 38 563 40 477,817 478,420 4 565 Consumer—other 488 155 131 774 34 157,662 158,470 41 138 Total $ 12,725 $ 2,591 $ 9,417 $ 24,733 $ 58,600 $ 7,231,171 $ 7,314,504 $ 952 $ 14,270 The following tables provide additional information on the allowance for loan losses and loan balances individually and collectively evaluated for impairment at or for the year ended December 31, 2016 (in thousands): For the Year Ended December 31, 2016 Commercial Real Estate Multifamily Real Estate Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance for loan losses: Beginning balance $ 20,716 $ 4,195 $ 27,131 $ 13,856 $ 3,645 $ 4,732 $ 902 $ 2,831 $ 78,008 Provision for loan losses 441 (2,835 ) 5,566 1,632 (170 ) (3,402 ) 4,079 719 6,030 Recoveries 582 — 2,171 1,993 59 1,283 610 — 6,698 Charge-offs (746 ) — (616 ) (948 ) (567 ) (375 ) (1,487 ) — (4,739 ) Ending balance $ 20,993 $ 1,360 $ 34,252 $ 16,533 $ 2,967 $ 2,238 $ 4,104 $ 3,550 $ 85,997 December 31, 2016 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance individually evaluated for impairment $ 428 $ 64 $ 374 $ 69 $ — $ 480 $ 5 $ — $ 1,420 Allowance collectively evaluated for impairment 20,565 1,296 33,845 16,464 2,967 1,758 4,099 3,550 84,544 Allowance for purchased credit-impaired loans — — 33 — — — — — 33 Total allowance for loan losses $ 20,993 $ 1,360 $ 34,252 $ 16,533 $ 2,967 $ 2,238 $ 4,104 $ 3,550 $ 85,997 December 31, 2016 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Loan balances: Loans individually evaluated for impairment $ 10,300 $ 349 $ 4,034 $ 2,946 $ 4,766 $ 7,678 $ 309 $ — $ 30,382 Loans collectively evaluated for impairment 3,305,586 247,662 815,174 1,201,112 363,706 805,125 650,079 — 7,388,444 Purchased credit-impaired loans 23,449 139 3,878 3,821 684 274 77 — 32,322 Total loans $ 3,339,335 $ 248,150 $ 823,086 $ 1,207,879 $ 369,156 $ 813,077 $ 650,465 $ — $ 7,451,148 The following tables provide additional information on the allowance for loan losses and loan balances individually and collectively evaluated for impairment at or for the year ended December 31, 2015 (in thousands): For the Year Ended December 31, 2015 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance for loan losses: Beginning balance $ 18,784 $ 4,562 $ 25,545 $ 12,043 $ 3,821 $ 5,447 $ 483 $ 5,222 $ 75,907 Provision for loan losses 1,177 (480 ) 666 1,611 (878 ) (1,068 ) 1,363 (2,391 ) — Recoveries 819 113 1,811 948 1,927 772 570 — 6,960 Charge-offs (64 ) — (891 ) (746 ) (1,225 ) (419 ) (1,514 ) — (4,859 ) Ending balance $ 20,716 $ 4,195 $ 27,131 $ 13,856 $ 3,645 $ 4,732 $ 902 $ 2,831 $ 78,008 December 31, 2015 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance individually evaluated for impairment $ 605 $ 71 $ 418 $ 69 $ — $ 728 $ 29 $ — $ 1,920 Allowance collectively evaluated for impairment 20,111 4,124 26,713 13,732 3,645 4,004 873 2,831 76,033 Allowance for purchased credit-impaired loans — — — 55 — — — — 55 Total allowance for loan losses $ 20,716 $ 4,195 $ 27,131 $ 13,856 $ 3,645 $ 4,732 $ 902 $ 2,831 $ 78,008 December 31, 2015 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Loan balances: Loans individually evaluated for impairment $ 8,519 $ 357 $ 4,669 $ 2,223 $ 544 $ 12,185 $ 319 $ — $ 28,816 Loans collectively evaluated for impairment 3,043,656 470,625 564,051 1,198,419 374,458 939,382 636,497 — 7,227,088 Purchased credit-impaired loans 40,985 1,994 5,650 7,302 1,529 1,066 74 — 58,600 Total loans $ 3,093,160 $ 472,976 $ 574,370 $ 1,207,944 $ 376,531 $ 952,633 $ 636,890 $ — $ 7,314,504

REAL ESTATE OWNED, HELD FOR SAL

REAL ESTATE OWNED, HELD FOR SALE, NET	12 Months Ended
	Dec. 31, 2016
Real Estate [Abstract]
REAL ESTATE OWNED, HELD FOR SALE, NET	REAL ESTATE OWNED, HELD FOR SALE, NET The following table presents the changes in REO, net of valuation allowance, for the years ended December 31, 2016 , 2015 and 2014 (in thousands): Years Ended December 31 2016 2015 2014 Balance, beginning of period $ 11,627 $ 3,352 $ 4,044 Additions from loan foreclosures 8,909 4,351 3,264 Additions from capitalized costs — 298 30 Additions from acquisitions 400 8,231 — Proceeds from dispositions of REO (10,812 ) (4,740 ) (4,923 ) Gain on sale of REO 1,833 351 973 Valuation adjustments in the period (876 ) (216 ) (36 ) Balance, end of period $ 11,081 $ 11,627 $ 3,352 At December 31, 2016, and 2015, the Company had $917,000 and $3.4 million , respectively, of foreclosed residential real estate properties held as REO. The recorded investment in one- to four-family residential loans in the process of foreclosure was $715,000 at December 31, 2016 and $2.8 million at December 31, 2015.

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT, NET	PROPERTY AND EQUIPMENT, NET Land, buildings and equipment owned by the Company and its subsidiaries at December 31, 2016 and 2015 are summarized as follows (in thousands): December 31 2016 2015 Land (1) $ 35,463 $ 38,992 Buildings and leasehold improvements (1) 162,342 160,075 Furniture and equipment 91,706 79,018 289,511 278,085 Less accumulated depreciation (123,030 ) (110,481 ) Property and equipment, net $ 166,481 $ 167,604 (1) The Company had $8.5 million and $1.9 million of properties held for sale that were included in land and buildings at December 31, 2016 and 2015 , respectively. The Company’s depreciation expense related to property and equipment was $13.5 million , $10.0 million , and $8.1 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. The Company’s rental expense was $16.7 million , $10.2 million , and $7.6 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. The Company’s obligations under long-term property leases are as follows: Year Amount 2017 $ 14.6 million 2018 12.7 million 2019 10.1 million 2020 8.8 million 2021 7.2 million Thereafter 16.1 million Total $ 69.5 million

DEPOSITS

DEPOSITS	12 Months Ended
	Dec. 31, 2016
Banking and Thrift [Abstract]
DEPOSITS	DEPOSITS Deposits consist of the following at December 31, 2016 and 2015 (in thousands): December 31 2016 2015 Non-interest-bearing checking $ 3,140,451 $ 2,619,618 Interest-bearing checking 914,484 1,159,846 Regular savings accounts 1,523,391 1,284,642 Money market accounts 1,497,755 1,637,092 Total interest-bearing transaction and savings accounts 3,935,630 4,081,580 Certificates of deposit: Certificates of deposit less than or equal to $250,000 884,403 1,168,495 Certificates of deposit greater than $250,000 160,930 185,375 Total certificates of deposit (1) 1,045,333 1,353,870 Total deposits $ 8,121,414 $ 8,055,068 Included in total deposits: Public fund transaction accounts $ 221,765 $ 209,430 Public fund interest-bearing certificates 25,650 31,281 Total public deposits $ 247,415 $ 240,711 Total brokered deposits $ 34,074 $ 162,936 (1) Certificates of deposit includes $426,000 and $2.0 million of acquisition premiums at December 31, 2016 and 2015 , respectively. Deposits at December 31, 2016 and 2015 included deposits from the Company’s directors, executive officers and related entities totaling $7.2 million and $6.6 million , respectively. At December 31, 2016 and 2015, the Company had certificates of deposit of $165.4 million and $192.3 million , respectively, that were equal to or greater than $250,000. Scheduled maturities and weighted average interest rates of certificate accounts at December 31, 2016 are as follows (dollars in thousands): December 31, 2016 Amount Weighted Average Rate Maturing in one year or less $ 765,406 0.45 % Maturing after one year through two years 159,436 0.76 Maturing after two years through three years 60,932 0.88 Maturing after three years through four years 26,238 1.19 Maturing after four years through five years 29,912 1.06 Maturing after five years 3,409 1.26 Total certificates of deposit $ 1,045,333 0.56 %

ADVANCES FROM FEDERAL HOME LOAN

ADVANCES FROM FEDERAL HOME LOAN BANK OF DES MOINES	12 Months Ended
	Dec. 31, 2016
Advances from Federal Home Loan Banks [Abstract]
ADVANCES FROM FEDERAL HOME LOAN BANK OF DES MOINES	ADVANCES FROM FEDERAL HOME LOAN BANK OF DES MOINES Utilizing a blanket pledge, qualifying loans receivable at December 31, 2016 and 2015 , were pledged as security for FHLB borrowings and there were no securities pledged as collateral as of December 31, 2016 or 2015 . At December 31, 2016 and 2015 , FHLB advances were scheduled to mature as follows (in thousands): December 31 2016 2015 Maturing in one year or less $ 54,000 $ 107,600 Maturing after one year through three years — 25,000 Maturing after three years through five years — — Maturing after five years 179 188 Total FHLB advances, at par 54,179 132,788 Fair value adjustment 37 593 Total FHLB advances, carried at fair value $ 54,216 $ 133,381 The maximum amount outstanding from the FHLB advances at month end for the years ended December 31, 2016 and 2015 was $300.2 million and $221.6 million , respectively. The average FHLB advances balance outstanding for the years ended December 31, 2016 and 2015 was $141.9 million and $45.0 million , respectively. The average contractual interest rate on the FHLB advances for the years ended December 31, 2016 and 2015 was 0.67% and 0.69% , respectively. As of December 31, 2016 , Banner Bank has established a borrowing line with the FHLB to borrow up to 35% of its total assets, contingent on having sufficient qualifying collateral and ownership of FHLB stock. Islanders Bank similarly may borrow up to 35% of its total assets, also contingent on collateral and FHLB stock. At December 31, 2016 , the maximum total FHLB credit line was $3.35 billion and $98.1 million for Banner Bank and Islanders Bank, respectively.

OTHER BORROWINGS

OTHER BORROWINGS	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
OTHER BORROWINGS	OTHER BORROWINGS Other borrowings consist of retail and wholesale repurchase agreements, other term borrowings and Federal Reserve Bank borrowings. Repurchase Agreements: At December 31, 2016 , retail repurchase agreements carry interest rates ranging from 0.15% to 0.40% . In addition to the retail repurchase agreements, Banner Bank had one wholesale repurchase agreement with an interest rate of 2.15% . These repurchase agreements are secured by the pledge of certain mortgage-backed and agency securities with a carrying value of $114.9 million . Banner Bank has the right to pledge or sell these securities, but it must replace them with substantially the same securities. Federal Reserve Bank of San Francisco and Other Borrowings: Banner Bank periodically borrows funds on an overnight basis from the Federal Reserve Bank through the Borrower-In-Custody (BIC) program. Such borrowings are secured by a pledge of eligible loans. At December 31, 2016 , based upon available unencumbered collateral, Banner Bank was eligible to borrow $1.02 billion from the Federal Reserve Bank, although, at that date, as well as at December 31, 2015 , the Bank had no funds borrowed under this or other borrowing arrangements. At December 31, 2016 , Banner Bank had an uncommitted federal funds line of credit agreement with another financial institution totaling $60.0 million , while Islanders Bank had an uncommitted federal funds line of credit agreement with another financial institution totaling $5.0 million . No balances were outstanding under these agreements as of December 31, 2016 and 2015 . Availability of lines is subject to federal funds balances available for loan and continued borrower eligibility. These lines are intended to support short-term liquidity needs and the agreements may restrict consecutive day usage. A summary of all other borrowings at December 31, 2016 and 2015 by the period remaining to maturity is as follows (dollars in thousands): At or for the Years Ended December 31 2016 2015 Amount Weighted Average Rate Amount Weighted Average Rate Repurchase agreements: Maturing in one year or less $ 100,685 0.19 % $ 93,325 0.19 % Maturing after one year through two years 5,000 2.15 — — Maturing after two years — — 5,000 2.15 Total year-end outstanding $ 105,685 0.28 $ 98,325 0.29 Average outstanding $ 108,427 0.29 $ 94,182 0.22 Maximum outstanding at any month-end 112,309 n/a 102,474 n/a

JUNIOR SUBORDINATED DEBENTURES

JUNIOR SUBORDINATED DEBENTURES AND MANDATORILY REDEEMABLE TRUST PREFERRED SECURITIES	12 Months Ended
	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
JUNIOR SUBORDINATED DEBENTURES AND MANDATORILY REDEEMABLE TRUST PREFERRED SECURITIES	JUNIOR SUBORDINATED DEBENTURES AND MANDATORILY REDEEMABLE TRUST PREFERRED SECURITIES At December 31, 2016 , the Company had nine wholly-owned subsidiary grantor trusts (the Trusts), which had issued $136.0 million of trust preferred securities to third parties, as well as $4.2 million of common capital securities, carried among other assets, which were issued to the Company. Trust preferred securities and common capital securities accrue and pay distributions periodically at specified annual rates as provided in the indentures. The Trusts used the proceeds from the offerings to purchase a like amount of junior subordinated debentures (the Debentures) of the Company. The Debentures are the sole assets of the Trusts. The Company’s obligations under the debentures and related documents, taken together, constitute a full and unconditional guarantee by the Company of the obligations of the Trusts. The trust preferred securities (TPS) are mandatorily redeemable upon the maturity of the Debentures, or upon earlier redemption as provided in the indentures. The Company has the right to redeem the Debentures in whole on or after specific dates, at a redemption price specified in the indentures plus any accrued but unpaid interest to the redemption date. All of the trust preferred securities issued by the Trusts qualified as Tier 1 capital as of December 31, 2016 . At December 31, 2016 , the Trusts comprised $136.0 million , or 11.2% of the Company’s total risk-based capital. The following table is a summary of trust preferred securities at December 31, 2016 (dollars in thousands): Name of Trust Aggregate Liquidation Amount of Trust Preferred Securities Aggregate Liquidation Amount of Common Capital Securities Aggregate Principal Amount of Junior Subordinated Debentures Stated Maturity (1) Current Interest Rate Reset Period Interest Rate Spread Banner Capital Trust II $ 15,000 $ 464 $ 15,464 2033 4.23 % Quarterly Three-month LIBOR + 3.35% Banner Capital Trust III 15,000 465 15,465 2033 3.78 Quarterly Three-month LIBOR + 2.90% Banner Capital Trust IV 15,000 465 15,465 2034 3.73 Quarterly Three-month LIBOR + 2.85% Banner Capital Trust V 25,000 774 25,774 2035 2.49 Quarterly Three-month LIBOR + 1.57% Banner Capital Trust VI 25,000 774 25,774 2037 2.46 Quarterly Three-month LIBOR + 1.62% Banner Capital Trust VII 25,000 774 25,774 2037 2.23 Quarterly Three-month LIBOR + 1.38% Siuslaw Statutory Trust I 8,000 248 8,248 2034 3.69 Quarterly Three-month LIBOR + 2.70% Greater Sacramento Bancorp Statutory Trust I 4,000 124 4,124 2033 4.23 Quarterly Three-month LIBOR + 3.35% Greater Sacramento Bancorp Statutory Trust II 4,000 124 4,124 2035 2.64 Quarterly Three-month LIBOR + 1.68% Total TPS liability at par $ 136,000 $ 4,212 140,212 3.03 % Fair value adjustment (45,012 ) Total TPS liability at fair value $ 95,200 (1) All of the Company's trust preferred securities are eligible for redemption.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The following table presents the components of the provision for income taxes included in the Consolidated Statements of Operations for the years ended December 31, 2016 , 2015 and 2014 (in thousands): Years Ended December 31 2016 2015 2014 Current Federal $ 29,787 $ 24,683 $ 23,411 State 2,477 1,399 1,444 Total Current 32,264 26,082 24,855 Deferred Federal 9,908 (3,310 ) 2,764 State 2,083 (23 ) (567 ) Total Deferred 11,991 (3,333 ) 2,197 Provision for income taxes $ 44,255 $ 22,749 $ 27,052 The following table presents the reconciliation of the federal statutory rate to the actual effective rate for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31 2016 2015 2014 Federal income tax statutory rate 35.0 % 35.0 % 35.0 % Increase (decrease) in tax rate due to: Tax-exempt interest (2.6 ) (3.9 ) (2.6 ) Investment in life insurance (1.2 ) (1.3 ) (0.8 ) State income taxes, net of federal tax offset 2.2 1.1 1.1 Tax credits (0.8 ) (1.6 ) (0.8 ) Merger and acquisition costs — 1.9 0.7 Other 1.5 2.3 0.7 Effective income tax rate 34.1 % 33.5 % 33.3 % The following table reflects the effect of temporary differences that gave rise to the components of the net deferred tax asset as of December 31, 2016 and 2015 (in thousands): December 31 2016 2015 Deferred tax assets: Loan loss and REO $ 36,719 $ 33,312 Deferred compensation 23,189 19,253 Net operating loss carryforward 82,714 91,893 Federal and state tax credits 7,711 7,877 State net operating losses 7,396 8,692 Loan discount 9,696 13,412 Other 6,217 5,620 Total deferred tax assets 173,642 180,059 Deferred tax liabilities: Depreciation (2,218 ) (1,103 ) Deferred loan fees, servicing rights and loan origination costs (13,291 ) (9,884 ) Intangibles (11,178 ) (13,320 ) Financial instruments accounted for under fair value accounting (16,186 ) (17,112 ) Unrealized (gain) loss on securities - available-for-sale (880 ) (1,475 ) Total deferred tax liabilities (43,753 ) (42,894 ) Deferred income tax asset 129,889 137,165 Valuation allowance (2,195 ) (2,195 ) Deferred tax asset, net $ 127,694 $ 134,970 At December 31, 2016 , the Company has federal net operating loss carryforwards of approximately $236.3 million . The Company also has $145.8 million state net operating loss carryforwards, which the Company has established a $2.2 million valuation reserve against. The federal and state net operating losses will expire, if unused, by the end of 2034 . The Company has federal general business credit carryforwards at December 31, 2016 of $3.3 million , which will expire, if unused, by the end of 2031 . The Company also has federal alternative minimum tax credit carryforwards of $4.2 million , which are available to reduce future federal regular income taxes, if any, over an indefinite period. Additionally, at December 31, 2016 , the Company has state credit carryovers of $193,000 . At December 31, 2015 , the Company had federal and state net operating loss carryforwards of approximately $262.5 million and $167.6 million , respectively, and federal general business credits carryforwards of $3.3 million . At that same date, the Company also had federal alternative minimum tax credit carryforwards of approximately $4.2 million . The 2015 state net operating loss carryovers obtained from acquisitions were previously reported on a partially tax effected basis as $23.0 million . As a consequence of our acquisition of Starbuck Bancshares, Inc., the Company experienced a change in control within the meaning of Section 382 of the Internal Revenue Code of 1986 (Code). In addition, the underlying Section 382 limitations at Starbuck Bancshares, Inc. prior to the Company's acquisition continue to apply to the Company. Section 382 limits the ability of a corporate taxpayer to use net operating loss carryforwards, general business credits, and recognized built-in-losses, on an annual basis, incurred prior to the change in control against income earned after the change in control. As a result of the Section 382 limitations, the Company is limited to utilizing $21.5 million (after the application of the Section 382 limitations carried over from Starbuck Bancshares, Inc.) of federal net operating loss carryforwards, general business credits, and recognized built-in losses on an annual basis. The applicable state Section 382 limitations range from $525,000 to $21.5 million . The Company has provided a $2.2 million valuation reserve against the portion of its various state net operating loss carryforwards and tax credits that it believes it is more likely than not that it will not realize the benefit because the application of the Section 382 limitations at the state level is based on future apportionment rates. In addition, as a consequence of Banner's capital raise in June 2010, the Company experienced a change in control within the meaning of Section 382 of the Code. As a result of the Section 382 limitations, the Company is limited to utilizing $6.9 million of net operating loss carryforwards which existed prior to the acquisition of Starbuck Bancshares, Inc., on an annual basis. Based on its analysis, the Company believes it is more likely than not that the June 2010 change in control will not impact its ability to utilize all of the related available net operating loss carryforwards, general business credits, and recognized built-in-losses. Retained earnings at December 31, 2016 and 2015 included approximately $5.4 million in tax basis bad debt reserves for which no income tax liability has been recorded. In the future, if this tax bad debt reserve is used for purposes other than to absorb bad debts or the Company no longer qualifies as a bank or is completely liquidated, the Company will incur a federal tax liability at the then-prevailing corporate tax rate, established as $1.9 million at December 31, 2016 . Tax credit investments: The Company invests in low income housing tax credit funds that are designed to generate a return primarily through the realization of federal tax credits. The Company accounts for these investments by amortizing the cost of tax credit investments over the life of the investment using a proportional amortization method and tax credit investment amortization expense is a component of the provision for income taxes. The following table presents the balances of the Company's tax credit investments and related unfunded commitments at December 31, 2016 and 2015 (in thousands): December 31, 2016 December 31, 2015 Tax credit investments $ 4,654 $ 5,326 Unfunded commitments—tax credit investments 665 1,398 The following table presents other information related to the Company's tax credit investments for the years ended December 31, 2016 and 2015 (in thousands): For the year ended December 31, 2016 2015 Tax credits and other tax benefits recognized $ 1,136 $ 1,273 Tax credit amortization expense included in provision for income taxes 672 1,000

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
EMPLOYEE BENEFIT PLANS	EMPLOYEE BENEFIT PLANS Employee Retirement Plans: Substantially all of the Company’s and the Banks' employees are eligible to participate in its 401(k)/Profit Sharing Plan, a defined contribution and profit sharing plan sponsored by the Company. Employees may elect to have a portion of their salary contributed to the plan in conformity with Section 401(k) of the Internal Revenue Code. At the discretion of the Company’s Board of Directors, the Company may elect to make matching and/or profit sharing contributions for the employees’ benefit. For the years ended December 31, 2016 , 2015 and 2014 , $4.6 million , $2.8 million and $1.4 million , respectively, was expensed for 401(k) contributions. The Board of Directors has elected to make a 4% of eligible compensation matching contribution for 2017 . Supplemental Retirement and Salary Continuation Plans: Through the Banks, the Company is obligated under various non-qualified deferred compensation plans to help supplement the retirement income of certain executives, including certain retired executives, selected by resolution of the Banks’ Boards of Directors or in certain cases by the former directors of acquired banks. These plans are unfunded, include both defined benefit and defined contribution plans, and provide for payments after the executive’s retirement. In the event of a participant employee’s death prior to or during retirement, the Company is obligated to pay to the designated beneficiary the benefits set forth under the plan. For the years ended December 31, 2016 , 2015 and 2014 , expense recorded for supplemental retirement and salary continuation plan benefits totaled $2.7 million , $1.3 million , and $1.2 million , respectively. At December 31, 2016 and 2015 , liabilities recorded for the various supplemental retirement and salary continuation plan benefits totaled $38.3 million and $39.0 million , respectively, and are recorded in a deferred compensation liability account. Deferred Compensation Plans and Rabbi Trusts: The Company and the Banks also offer non-qualified deferred compensation plans to members of their Boards of Directors and certain employees. The plans permit each participant to defer a portion of director fees, non-qualified retirement contributions, salary or bonuses for future receipt. Compensation is charged to expense in the period earned. In connection with its acquisitions, the Company also assumed liability for certain deferred compensation plans for key employees, retired employees and directors. In order to fund the plans’ future obligations, the Company has purchased life insurance policies or other investments, including Banner Corporation common stock, which in certain instances are held in irrevocable trusts commonly referred to as “Rabbi Trusts.” As the Company is the owner of the investments and the beneficiary of the insurance policies, and in order to reflect the Company’s policy to pay benefits equal to the accumulations, the assets and liabilities are reflected in the Consolidated Statements of Financial Condition. Banner Corporation common stock held for such plans is reported as a contra-equity account and was recorded at an original cost of $7.3 million at December 31, 2016 and $6.9 million at December 31, 2015 . At December 31, 2016 and 2015 , liabilities recorded in connection with deferred compensation plan benefits totaled $9.0 million ( $7.3 million in contra-equity) and $8.4 million ( $6.9 million in contra-equity), respectively, and are recorded in deferred compensation or equity as appropriate. The Banks have purchased, or acquired through mergers, life insurance policies in connection with the implementation of certain executive supplemental retirement, salary continuation and deferred compensation retirement plans, as well as additional policies not related to any specific plan. These policies provide protection against the adverse financial effects that could result from the death of a key employee and provide tax-exempt income to offset expenses associated with the plans. It is the Banks’ intent to hold these policies as a long-term investment. However, there will be an income tax impact if the Banks choose to surrender certain policies. Although the lives of individual current or former management-level employees are insured, the Banks are the owners and sole or partial beneficiaries. At December 31, 2016 and 2015 , the cash surrender value of these policies was $158.9 million and $156.9 million , respectively. The Banks are exposed to credit risk to the extent an insurance company is unable to fulfill its financial obligations under a policy. In order to mitigate this risk, the Banks use a variety of insurance companies and regularly monitor their financial condition.

STOCK-BASED COMPENSATION PLANS

STOCK-BASED COMPENSATION PLANS	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION PLANS	STOCK-BASED COMPENSATION PLANS The Company operates the following stock-based compensation plans as approved by its shareholders: • 2001 Stock Option Plan (the SOP). • 2012 Restricted Stock and Incentive Bonus Plan. • 2014 Omnibus Incentive Plan. The purpose of these plans is to promote the success and enhance the value of the Company by providing a means for attracting and retaining highly skilled employees, officers and directors of Banner Corporation and its affiliates and linking their personal interests with those of the Company's shareholders. Under these plans the Company currently has outstanding restricted stock share grants, restricted stock unit grants, and stock options. Stock Options Under the SOP, Banner reserved 68,571 shares for issuance pursuant to the exercise of stock options to be granted to directors and employees. Authority to grant additional options under the 2001 Stock Option Plan terminated on April 20, 2011. The exercise price of the stock options is set at 100% of the fair market value of the stock price on the date of grant. Options granted vest at a rate of 20% per year from the date of grant and any unexercised incentive stock options will expire ten years after date of grant or 90 days after employment or service ends. During the years ended December 31, 2016 , 2015 and 2014 , the Company did no t grant any stock options and there were no stock options forfeited. Additionally, there were no significant modifications made to any stock option grants during the period. The fair values of stock options granted are amortized as compensation expense on a straight-line basis over the vesting period of the grant. For the years ended December 31, 2016 , 2015 and 2014 there were no stock option compensation expenses recorded. The intrinsic value of stock options is calculated as the amount by which the market price of Banner's common stock exceeds the exercise price at the time of exercise or the end of the period as applicable. At December 31, 2016 , financial data pertaining to outstanding stock options was as follows: Exercise Price Weighted Average Exercise Price of Option Shares Granted Number of Option Shares Granted Weighted Average Option Shares Vested and Exercisable Weighted Average Exercise Price of Option Shares Exercisable Remaining Contractual Life $ 216.16 $ 216.16 5,000 5,000 $ 216.16 7 months During the year ended December 31, 2016 , there were no exercises of stock options. Cash was not used to settle any equity instruments previously granted. The Company issues shares from authorized but unissued shares upon the exercise of stock options. The Company does not currently expect to repurchase shares from any source to satisfy such obligations under the SOP. 2012 Restricted Stock and Incentive Bonus Plan Under the 2012 Restricted Stock and Incentive Bonus Plan (2012 Restricted Stock Plan), which was initially 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 2012 Restricted Stock Plan have a minimum vesting period of three years. The 2012 Restricted Stock Plan will continue in effect for a term of ten years, after which no further awards may be granted. 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. Vesting requirements may include time-based conditions, performance-based conditions, and/or market-based conditions. As of December 31, 2016 , the Company had granted 297,157 shares of restricted stock from the 2012 Restricted Stock Plan (as amended and restated), of which 207,338 shares had vested and 89,819 shares remain unvested. 2014 Omnibus Incentive Plan The 2014 Omnibus Incentive Plan (the 2014 Plan) was approved by shareholders on April 22, 2014. The 2014 Plan provides for the grant of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, other stock-based awards and other cash awards, and provides for vesting requirements which may include time-based or performance-based conditions. The Company has reserved 900,000 shares of its common stock for issuance under the 2014 Plan in connection with the exercise of awards. As of December 31, 2016 , 239,088 restricted stock shares and 26,154 restricted stock units have been granted under the 2014 Plan of which 46,011 restricted stock shares and 18,331 restricted stock units have vested. The expense associated with all restricted stock grants was $4.5 million , $3.5 million and $2.7 million respectively, for the years ended December 31, 2016 , 2015 and 2014 . Unrecognized compensation expense for these awards as of December 31, 2016 was $6.8 million and will be amortized over the next 36 months. A summary of the Company's Restricted Stock/Unit award activity during the years ended December 31, 2014 , 2015 and 2016 follows: Shares/Units Weighted Average Grant-Date Fair Value Unvested at December 31, 2013 164,492 $ 26.94 Granted 90,181 40.07 Vested (56,307 ) 24.81 Forfeited (3,260 ) 31.00 Unvested at December 31, 2014 195,106 32.83 Granted 155,183 45.59 Vested (109,416 ) 30.28 Forfeited (9,311 ) 39.07 Unvested at December 31, 2015 231,562 42.33 Granted 177,775 41.74 Vested (104,297 ) 41.47 Forfeited (14,321 ) 42.54 Unvested at December 31, 2016 290,719 42.26

PREFERRED STOCK AND RELATED WAR

PREFERRED STOCK AND RELATED WARRANT	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
PREFERRED STOCK AND RELATED WARRANT	PREFERRED STOCK AND RELATED WARRANT On November 21, 2008, as part of the Capital Purchase Program, the Company entered into a Purchase Agreement with U.S. Treasury pursuant to which the Company issued and sold 124,000 shares of Series A Preferred Stock, having a liquidation preference of $1,000 per share ( $124 million liquidation preference in the aggregate) and a ten -year warrant to purchase up to 243,998 shares of the Company’s common stock, par value $0.01 per share, at an initial exercise price of $76.23 per share (post reverse-split), for an aggregate purchase price of $18.6 million in cash. During the year ended December 31, 2012, the Company repurchased or redeemed 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 U.S. 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.

REGULATORY CAPITAL REQUIREMENTS

REGULATORY CAPITAL REQUIREMENTS	12 Months Ended
	Dec. 31, 2016
Regulatory Capital Requirements [Abstract]
REGULATORY CAPITAL REQUIREMENTS	REGULATORY CAPITAL REQUIREMENTS Banner Corporation is a bank holding company registered with the Federal Reserve. Bank holding companies are subject to capital adequacy requirements of the Federal Reserve under the Bank Holding Company Act of 1956, as amended (BHCA), and the regulations of the Federal Reserve. Banner Bank and Islanders Bank, as state-chartered federally insured commercial banks, are subject to the capital requirements established by the FDIC. The Federal Reserve requires Banner to maintain capital adequacy that generally parallels the FDIC requirements. The following table shows the regulatory capital ratios of the Company and the Banks and the minimum regulatory requirements (dollars in thousands): Actual Minimum for Capital Adequacy Purposes Minimum to be Categorized as “Well-Capitalized” Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio December 31, 2016: The Company—consolidated: Total capital to risk-weighted assets $ 1,214,913 13.40 % $ 725,566 8.00 % $ 906,957 10.00 % Tier 1 capital to risk-weighted assets 1,125,267 12.41 544,174 6.00 544,174 6.00 Tier 1 common equity to risk-weighted assets 1,014,994 11.19 408,131 4.50 n/a n/a Tier 1 capital to average leverage assets 1,125,267 11.83 380,519 4.00 n/a n/a Banner Bank: Total capital to risk- weighted assets 1,043,837 11.76 709,882 8.00 887,352 10.00 Tier 1 capital to risk- weighted assets 956,298 10.78 532,411 6.00 709,882 8.00 Tier 1 common equity to risk-weighted assets 956,298 10.78 399,308 4.50 576,779 6.50 Tier 1 capital to average leverage assets 956,298 10.34 369,936 4.00 462,420 5.00 Islanders Bank: Total capital to risk- weighted assets 35,207 18.43 15,281 8.00 19,101 10.00 Tier 1 capital to risk- weighted assets 33,099 17.33 11,461 6.00 15,281 8.00 Tier 1 common equity to risk-weighted assets 33,099 17.33 8,598 4.50 12,416 6.50 Tier 1 capital to average leverage assets 33,099 12.72 10,405 4.00 13,006 5.00 December 31, 2015: The Company—consolidated: Total capital to risk-weighted assets $ 1,139,554 13.63 % $ 668,941 8.00 % $ 836,530 10.00 % Tier 1 capital to risk-weighted assets 1,057,597 12.65 501,706 6.00 501,918 6.00 Tier 1 common equity to risk-weighted assets 1,013,971 12.13 376,279 4.50 n/a n/a Tier 1 capital to average leverage assets 1,057,597 11.06 382,617 4.00 n/a n/a Banner Bank: Total capital to risk- weighted assets 1,030,601 12.61 653,606 8.00 817,008 10.00 % Tier 1 capital to risk- weighted assets 950,865 11.64 490,205 6.00 653,606 8.00 Tier 1 common equity to risk-weighted assets 950,865 11.64 367,653 4.50 531,055 6.50 Tier 1 capital to average leverage assets 950,865 10.23 371,807 4.00 464,759 5.00 Islanders Bank: Total capital to risk- weighted assets 38,448 20.31 15,146 8.00 18,932 10.00 Tier 1 capital to risk- weighted assets 36,227 19.14 11,359 6.00 15,146 8.00 Tier 1 common equity to risk-weighted assets 36,227 19.14 8,520 4.50 12,306 6.50 Tier 1 capital to average leverage assets 36,227 13.38 10,826 4.00 13,533 5.00 At December 31, 2016 , Banner Corporation and the Banks each exceeded all regulatory capital adequacy requirements. There have been no conditions or events since December 31, 2016 that have materially adversely changed the Tier 1 or Tier 2 capital of the Company or the Banks. However, events beyond the control of the Banks, such as weak or depressed economic conditions in areas where the Banks have most of their loans, could adversely affect future earnings and, consequently, the ability of the Banks to meet their respective capital requirements. The Company may not declare or pay cash dividends on, or repurchase, any of its shares of common stock if the effect thereof would cause equity to be reduced below applicable regulatory capital maintenance requirements or if such declaration and payment would otherwise violate regulatory requirements. On July 2, 2013, the Federal Reserve approved a final rule (Final Rule) to establish a new comprehensive regulatory capital framework for all U.S. financial institutions and their holding companies. On July 9, 2013, the Final Rule was approved as an interim final rule by the FDIC. The Final Rule implements the “Basel III” regulatory capital reforms and changes required by the Dodd-Frank Act. The Final Rule includes new risk-based capital and leverage ratios, which were effective January 1, 2015 and revised the definition of what constitutes “capital” for purposes of calculating those ratios. Effective January 1, 2015 (with some changes transitioned into full effectiveness over two to four years), Banner and the Banks became subject to the new capital requirements adopted by the Federal Reserve and the FDIC. These new requirements created a new required ratio for common equity Tier 1 (CET1) capital, increased the leverage and Tier 1 capital ratios, changed the risk-weights of certain assets for purposes of the risk-based capital ratios, created an additional capital conservation buffer over the required capital ratios and changed what qualifies as capital for purposes of meeting these various capital requirements. Beginning in 2016, failure to maintain the required capital conservation buffer will limit Banner's ability and the ability of the Banks to pay dividends, repurchase shares or pay discretionary bonuses. Under the new capital regulations, the minimum capital ratios applicable to Banner and the Banks are: (i) a CETI capital ratio of 4.5%; (ii) a Tier 1 capital ratio of 6% (increased from 4%); (iii) a total capital ratio of 8% (unchanged from prior rules); and (iv) a Tier 1 leverage ratio of 4% for all institutions. CET1 generally consists of common stock; retained earnings; accumulated other comprehensive income (AOCI), unless an election is made to exclude AOCI from regulatory capital, as discussed below; and certain minority interests; all subject to applicable regulatory adjustments and deductions. There are a number of changes in what constitutes regulatory capital, some of which are subject to transition periods. These changes include the phasing-out of certain instruments as qualifying capital. Banner and the Banks do not have any of these instruments. Under the new requirements for total capital, Tier 2 capital is no longer limited to the amount of Tier 1 capital included in total capital. Mortgage servicing rights, certain deferred tax assets and investments in unconsolidated subsidiaries over designated percentages of CET1 will be deducted from capital. In the first quarter of 2015, we elected to permanently opt-out of the inclusion of AOCI in our capital calculations, to reduce the impact of market volatility on our regulatory capital levels. The new requirements also included changes in the risk-weights of certain assets to better reflect credit risk and other risk exposures. These included a 150% risk weight (up from 100%) for certain high volatility commercial real estate acquisition, development and construction loans and for non-residential mortgage loans that are 90 days past due or otherwise in non-accrual status; a 20% (up from 0%) credit conversion factor for the unused portion of a commitment with an original maturity of one year or less that is not unconditionally cancellable (up from 0%); a 250% risk weight (up from 100%) for mortgage servicing and deferred tax assets that are not deducted from capital; and increased risk-weights (0% to 600%) for equity exposures. In addition to the minimum CET1, Tier 1, total capital and leverage ratios, Banner and each of the Banks now have to maintain a capital conservation buffer consisting of additional CET1 capital above the required minimum levels in order to avoid limitations on paying dividends, engaging in share repurchases, and paying discretionary bonuses based on percentages of eligible retained income that could be utilized for such actions. This new capital conservation buffer requirement began to be phased in starting in January 2016 at 0.625% of risk-weighted assets and will increase each year until fully implemented to an amount equal to 2.5% of risk-weighted assets in January 2019.

GOODWILL, OTHER INTANGIBLE ASSE

GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS	12 Months Ended
	Dec. 31, 2016
Other Intangible Assets and Mortgage Servicing Rights [Abstract]
OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS	GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS Goodwill and Other Intangible Assets: At December 31, 2016 , intangible assets are comprised of goodwill, CDI, and LHI acquired in business combinations. Goodwill represents the excess of the total purchase price paid over the fair value of the assets acquired, net of the fair values of liabilities assumed, and is not amortized but is reviewed annually for impairment. Banner has identified one reporting unit for purposes of evaluating goodwill for impairment. At December 31, 2016 , the Company completed a qualitative assessment of goodwill and concluded that it is more likely than not that the fair value of Banner, the reporting unit, exceeds the carrying value. Additions to goodwill during the year ended December 31, 2015 relate to the Starbuck and Siuslaw acquisitions. The adjustments to goodwill in 2016 related to changes in the preliminary goodwill recorded for the Starbuck acquisition including adjustments to loan discount, deferred taxes and REO valuations. See Note 3, Business Combinations, for additional information on the acquisition and purchase price allocation. CDI represents the value of transaction-related deposits and the value of the customer relationships associated with the deposits. LHI represents the value ascribed to leases assumed in an acquisition in which the lease terms are favorable compared to a market lease at the date of acquisition. The Company amortizes CDI and LHI over their estimated useful lives and reviews them at least annually for events or circumstances that could impair their value. The CDI assets shown in the table below represent the value ascribed to the long-term deposit relationships acquired in various bank acquisitions. The additions in the table below relate to the acquisition of Siuslaw and Starbuck in 2015. These intangible assets are being amortized using an accelerated method over estimated useful lives of three to ten years. The CDI and LHI assets are not estimated to have a significant residual value. The following table summarizes the changes in the Company’s goodwill, CDI and LHI for the years ended December 31, 2014 , 2015 and 2016 (in thousands): Goodwill CDI LHI Total Balance, December 31, 2013 $ — $ 2,449 $ — $ 2,449 Additions through acquisition — 2,372 — 2,372 Amortization — (1,990 ) — (1,990 ) Balance, December 31, 2014 — 2,831 — 2,831 Additions through acquisition 247,738 37,395 776 285,909 Amortization — (3,164 ) (66 ) (3,230 ) Other Changes (1) — (300 ) — (300 ) Balance, December 31, 2015 247,738 36,762 710 285,210 Amortization — (7,061 ) (249 ) (7,310 ) Adjustments to goodwill (3,155 ) — — (3,155 ) Balance, December 31, 2016 $ 244,583 $ 29,701 $ 461 $ 274,745 (1) Acquired CDI from Starbuck was adjusted for a branch that was subsequently sold. Estimated amortization expense in future years with respect to CDI as of December 31, 2016 (in thousands): Year ended: Estimated Amortization 2017 $ 6,332 2018 5,609 2019 4,889 2020 4,169 Thereafter 8,702 Net carrying amount $ 29,701 Mortgage servicing rights are reported in other assets. Mortgage servicing rights are initially recognized at fair value and are amortized in proportion to, and over the period of, the estimated future net servicing income of the underlying financial assets. Mortgage servicing rights are subsequently evaluated for impairment based upon the fair value of the rights compared to the amortized cost (remaining unamortized initial fair value). If the fair value is less than the amortized cost, a valuation allowance is created through an impairment charge to servicing fee income. However, if the fair value is greater than the amortized cost, the amount above the amortized cost is not recognized in the carrying value. In 2016 and 2015 , the Company did no t record any impairment charges or recoveries against mortgage servicing rights. Unpaid principal balance of loans for which mortgage servicing rights have been recognized totaled $2.05 billion and $1.86 billion at December 31, 2016 and 2015 , respectively. Custodial accounts maintained in connection with this servicing totaled $10.3 million and $8.7 million at December 31, 2016 and 2015 , respectively. An analysis of the mortgage servicing rights for the years ended December 31, 2016 , 2015 and 2014 is presented below (in thousands): Years Ended December 31 2016 2015 2014 Balance, beginning of the year $ 13,295 $ 9,030 $ 8,086 Amounts capitalized 5,965 5,313 3,023 Additions through acquisition — 2,172 — Amortization (1) (4,011 ) (3,220 ) (2,079 ) Balance, end of the year (2) $ 15,249 $ 13,295 $ 9,030 (1) Amortization of mortgage servicing rights is recorded as a reduction of loan servicing income and any unamortized balance is fully written off if the loan repays in full. (2) There was no valuation allowance as of December 31, 2016 , 2015 and 2014 .

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS	FAIR VALUE The following table presents estimated fair values of the Company’s financial instruments as of December 31, 2016 and 2015 , whether or not recognized or recorded in the Consolidated Statements of Financial Condition (in thousands): December 31, 2016 December 31, 2015 Level Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Assets: Cash and due from banks 1 $ 247,719 $ 247,719 $ 261,917 $ 261,917 Securities—trading 2,3 24,568 24,568 34,134 34,134 Securities—available-for-sale 2 800,917 800,917 1,138,573 1,138,573 Securities—held-to-maturity 2,3 267,873 270,528 220,666 226,627 Loans receivable held for sale 2 246,353 246,815 44,712 45,600 Loans receivable 3 7,451,148 7,337,608 7,314,504 7,084,631 FHLB stock 3 12,506 12,506 16,057 16,057 BOLI 1 158,936 158,936 156,865 156,865 Mortgage servicing rights 3 15,249 16,740 13,295 17,370 Derivatives: Interest rate swaps 2 8,330 8,330 11,984 11,984 Interest rate lock and forward sales commitments 2 482 482 471 471 Liabilities: Demand, interest-bearing checking and money market 2 5,552,690 5,552,690 5,416,556 5,416,556 Regular savings 2 1,523,391 1,523,391 1,284,642 1,284,642 Certificates of deposit 2 1,045,333 1,028,866 1,353,870 1,332,825 Advances from FHLB at fair value 2 54,216 54,216 133,381 133,381 Junior subordinated debentures at fair value 3 95,200 95,200 92,480 92,480 Other borrowings 2 105,685 105,685 98,325 98,325 Derivatives: Interest rate swaps 2 8,330 8,330 11,984 11,984 Interest rate lock and forward sales commitments 2 289 289 50 50 The Company measures and discloses certain assets and liabilities at fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (that is, not a forced liquidation or distressed sale). GAAP establishes a consistent framework for measuring fair value and disclosure requirements about fair value measurements. Among other things, the standard requires us to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company’s estimates for market assumptions. These two types of inputs create the following fair value hierarchy: • Level 1 – Quoted prices in active markets for identical instruments. An active market is a market in which transactions occur with sufficient frequency and volume to provide pricing information on an ongoing basis. A quoted price in an active market provides the most reliable evidence of fair value and shall be used to measure fair value whenever available. • Level 2 – Observable inputs other than Level 1 including quoted prices in active markets for similar instruments, quoted prices in less active markets for identical or similar instruments, or other observable inputs that can be corroborated by observable market data. • Level 3 – Unobservable inputs supported by little or no market activity for financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation; also includes observable inputs from non-binding single dealer quotes not corroborated by observable market data. In developing Level 3 measurements, management incorporates whatever market data might be available and uses discounted cash flow models where appropriate. These calculations include projections of future cash flows, including appropriate default and loss assumptions, and market based discount rates. The estimated fair value amounts of financial instruments have been determined by the Company using available market information and appropriate valuation methodologies. However, considerable judgment is required to interpret data to develop the estimates of fair value. Accordingly, the estimates presented herein are not necessarily indicative of the amounts the Company could realize at a future date. The use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts. In addition, reasonable comparability between financial institutions may not be likely due to the wide range of permitted valuation techniques and numerous estimates that must be made given the absence of active secondary markets for many of the financial instruments. This lack of uniform valuation methodologies also introduces a greater degree of subjectivity to these estimated fair values. Transfers between levels of the fair value hierarchy are deemed to occur at the end of the reporting period. Items Measured at Fair Value on a Recurring Basis: The following tables present financial assets and liabilities measured at fair value on a recurring basis and the level within the fair value hierarchy of the fair value measurements for those assets and liabilities as of December 31, 2016 and 2015 (in thousands): December 31, 2016 Level 1 Level 2 Level 3 Total Assets: Securities—trading U.S. Government and agency $ — $ 1,326 $ — $ 1,326 Municipal bonds — 335 — 335 Corporate Bonds (TPS securities) — — 21,143 21,143 Mortgage-backed securities — 1,641 — 1,641 Equity securities — 123 — 123 — 3,425 21,143 24,568 Securities—available-for-sale U.S. Government and agency $ — $ 56,978 $ — $ 56,978 Municipal bonds — 109,853 — 109,853 Corporate bonds — 10,283 — 10,283 Mortgage-backed securities — 594,712 — 594,712 Asset-backed securities — 28,993 — 28,993 Equity securities — 98 — 98 — 800,917 — 800,917 Loans held for sale — 9,600 — 9,600 Derivatives Interest rate lock and forward sales commitments — 482 — 482 Interest rate swaps — 8,330 — 8,330 $ — $ 822,754 $ 21,143 $ 843,897 Liabilities Advances from FHLB at fair value $ — $ 54,216 $ — $ 54,216 Junior subordinated debentures at fair value — — 95,200 95,200 Derivatives Interest rate lock and forward sales commitments — 289 — 289 Interest rate swaps — 8,330 — 8,330 $ — $ 62,835 $ 95,200 $ 158,035 December 31, 2015 Level 1 Level 2 Level 3 Total Assets: Securities—trading U.S. Government and agency $ — $ 1,368 $ — $ 1,368 Municipal bonds — 341 — 341 Corporate Bonds (TPS securities) — — 18,699 18,699 Mortgage-backed securities — 13,663 — 13,663 Equity securities — 63 — 63 — 15,435 18,699 34,134 Securities—available-for-sale U.S. Government and agency $ — $ 30,231 $ — $ 30,231 Municipal bonds — 143,319 — 143,319 Corporate bonds — 15,981 — 15,981 Mortgage-backed securities — 918,259 — 918,259 Asset-backed securities — 30,685 — 30,685 Equity securities — 98 — 98 — 1,138,573 — 1,138,573 Derivatives Interest rate lock and forward sales commitments — 471 — 471 Interest rate swaps — 11,984 — 11,984 $ — $ 1,166,463 $ 18,699 $ 1,185,162 Liabilities Advances from FHLB at fair value $ — $ 133,381 $ — $ 133,381 Junior subordinated debentures at fair value — — 92,480 92,480 Derivatives Interest rate lock and forward sales commitments — 50 — 50 Interest rate swaps — 11,984 — 11,984 $ — $ 145,415 $ 92,480 $ 237,895 The following methods were used to estimate the fair value of each class of financial instruments: Cash and Cash Equivalents: The carrying amount of these items is a reasonable estimate of their fair value. Securities: The estimated fair values of investment securities and mortgaged-backed securities are priced using current active market quotes, if available, which are considered Level 1 measurements. For most of the portfolio, matrix pricing based on the securities’ relationship to other benchmark quoted prices is used to establish the fair value. These measurements are considered Level 2. Due to the continued limited activity in the trust preferred markets that have limited the observability of market spreads for some of the Company’s TPS securities, management has classified these securities as a Level 3 fair value measure. Management periodically reviews the pricing information received from third-party pricing services and tests those prices against other sources to validate the reported fair values. Loans Held for Sale: Fair values for residential mortgage loans held for sale are determined by comparing actual loan rates to current secondary market prices for similar loans. Fair values for multifamily loans held for sale are calculated using recent sales data for comparable loans. Loans Receivable: Fair values are estimated first by stratifying the portfolios of loans with similar financial characteristics. Loans are segregated by type such as multifamily real estate, residential mortgage, nonresidential mortgage, commercial/agricultural, consumer and other. Each loan category is further segmented into fixed- and adjustable-rate interest terms. A preliminary estimate of fair value is then calculated based on discounted cash flows using as a discount rate the current rate offered on similar products, plus an adjustment for liquidity to reflect the non-homogeneous nature of the loans. The preliminary estimate is then further reduced by the amount of the allowance for loan losses to arrive at a final estimate of fair value. Fair value for impaired loans is also based on recent appraisals or estimated cash flows discounted using rates commensurate with risk associated with the estimated cash flows. Assumptions regarding credit risk, cash flows and discount rates are judgmentally determined using available market information and specific borrower information. FHLB Stock: The fair value is based upon the redemption value of the stock which equates to its carrying value. Bank-Owned Life Insurance: The fair value of BOLI policies owned is based on the various insurance contracts' cash surrender value. Mortgage Servicing Rights: Fair values are estimated based on an independent dealer analysis of discounted cash flows. The evaluation utilizes assumptions market participants would use in determining fair value including prepayment speeds, delinquency and foreclosure rates, the discount rate, servicing costs, and the timing of cash flows. The mortgage servicing portfolio is stratified by loan type and fair value estimates are adjusted up or down based on the serviced loan interest rates versus current rates on new loan originations since the most recent independent analysis. Deposits: The carrying amount of deposits with no stated maturity, such as savings and checking accounts, is a reasonable estimate of their fair value. The market value of certificates of deposit is based upon the discounted value of contractual cash flows. The discount rate is determined using the rates currently offered on comparable instruments. FHLB Advances: Fair valuations for Banner’s FHLB advances are estimated using fair market values provided by the lender, the FHLB of Des Moines. The FHLB of Des Moines prices advances by discounting the future contractual cash flows for individual advances, using its current cost of funds curve to provide the discount rate. Junior Subordinated Debentures: The fair value of junior subordinated debentures is estimated using an income approach technique. The significant inputs included in the estimation of fair value are the credit risk adjusted spread and three month LIBOR. The credit risk adjusted spread represents the nonperformance risk of the liability. The Company utilizes an external valuation firm to validate the reasonableness of the credit risk adjusted spread used to determine the fair value. The junior subordinated debentures are carried at fair value which represents the estimated amount that would be paid to transfer these liabilities in an orderly transaction amongst market participants. Due to credit concerns in the capital markets and inactivity in the trust preferred markets that have limited the observability of market spreads, management has classified this as a Level 3 fair value measure. Other Borrowings: Other borrowings include securities sold under agreements to repurchase and occasionally federal funds purchased and their carrying amount is considered a reasonable approximation of their fair value. Derivatives: Derivatives include interest rate swap agreements, interest rate lock commitments to originate loans held for sale and forward sales contracts to sell loans and securities related to mortgage banking activities. Fair values for these instruments, which generally change as a result of changes in the level of market interest rates, are estimated based on dealer quotes and secondary market sources. Off-Balance Sheet Items: Off-balance sheet financial instruments include unfunded commitments to extend credit, including standby letters of credit, and commitments to purchase investment securities. The fair value of these instruments is not considered to be material. Limitations: The fair value estimates presented herein are based on pertinent information available to management as of December 31, 2016 and 2015 . The factors used in the fair value estimates are subject to change subsequent to the dates the fair value estimates are completed, therefore, current estimates of fair value may differ significantly from the amounts presented herein. Assets and Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3) The following table provides a description of the valuation technique, unobservable inputs, and qualitative information about the unobservable inputs for the Company's assets and liabilities classified as Level 3 and measured at fair value on a recurring and nonrecurring basis at December 31, 2016 : December 31 2016 Financial Instruments Valuation Technique Unobservable Inputs Weighted Average Rate Corporate Bonds (TPS securities) Discounted cash flows Discount rate 6.00 % Junior subordinated debentures Discounted cash flows Discount rate 6.00 % REO Appraisals Discount to appraised value 0% to 45% TPS Securities : Management believes that the credit risk-adjusted spread used to develop the discount rate utilized in the fair value measurement of TPS securities is indicative of the risk premium a willing market participant would require under current market conditions for instruments with similar contractual rates, terms and conditions and issuers with similar credit risk profiles and with similar expected probability of default. Management attributes the change in fair value of these instruments, compared to their par value, primarily to perceived general market adjustments to the risk premiums for these types of assets subsequent to their issuance. Junior subordinated debentures : Similar to the TPS securities discussed above, management believes that the credit risk-adjusted spread utilized in the fair value measurement of the junior subordinated debentures is indicative of the risk premium a willing market participant would require under current market conditions for an issuer with Banner's credit risk profile. Management attributes the change in fair value of the junior subordinated debentures, compared to their par value, primarily to perceived general market adjustments to the risk premiums for these types of liabilities subsequent to their issuance. Future contractions in the risk adjusted spread relative to the spread currently utilized to measure the Company's junior subordinated debentures at fair value as of December 31, 2016, or the passage of time, will result in negative fair value adjustments. At December 31, 2016, the discount rate utilized was based on a credit spread of 500 basis points and three month LIBOR of 100 basis points. The following table provides a reconciliation of the assets and liabilities measured at fair value using significant unobservable inputs (Level 3) on a recurring basis during the year ended December 31, 2016 and 2015 (in thousands): Year Ended December 31, 2016 Level 3 Fair Value Inputs TPS Securities Borrowings— Junior Subordinated Debentures Beginning balance at December 31, 2015 $ 18,699 $ 92,480 Total gains or losses recognized Assets gains 719 — Liabilities losses — 2,720 Purchases, issuances and settlements, net 1,725 — Paydowns and maturities — — Transfers in and/or out of Level 3 — — Ending balance at December 31, 2016 $ 21,143 $ 95,200 Year Ended December 31, 2015 Level 3 Fair Value Inputs TPS and TRUP CDOs Borrowings— Junior Subordinated Debentures Beginning balance at December 31, 2014 $ 19,119 $ 78,001 Total gains or losses recognized Assets gains 537 — Liabilities losses — 2,714 Purchases, issuances and settlements 5,697 11,765 Paydowns and maturities (6,654 ) — Ending balance at December 31, 2015 $ 18,699 $ 92,480 The Company has elected to continue to recognize the interest income and dividends from the securities reclassified to fair value as a component of interest income as was done in prior years when they were classified as available-for-sale. Interest expense related to the FHLB advances and junior subordinated debentures continues to be measured based on contractual interest rates and reported in interest expense. The change in fair value of these financial instruments has been recorded as a component of non-interest income. Items Measured at Fair Value on a Non-recurring Basis The following table presents financial assets and liabilities measured at fair value on a non-recurring basis and the level within the fair value hierarchy of the fair value measurements for those assets at December 31, 2016 and 2015 (in thousands): December 31, 2016 Level 1 Level 2 Level 3 Total REO $ — $ — $ 11,081 $ 11,081 December 31, 2015 Level 1 Level 2 Level 3 Total Impaired loans $ — $ — $ 2,372 $ 2,372 REO — — 11,627 11,627 The following table presents the losses resulting from non-recurring fair value adjustments for the years ended December 31, 2016 and 2015 (in thousands): For the year ended December 31, 2016 2015 Impaired loans $ (182 ) $ (110 ) REO (671 ) (231 ) Total loss from nonrecurring measurements $ (853 ) $ (341 ) Impaired loans : Impaired loans are measured based on the present value of expected future cash flows discounted at the loan's effective interest rate or, as a practical expedient, at the loan's observable market price or the fair value of collateral if the loan is collateral dependent. If this practical expedient is used, the impaired loans are considered to be held at fair value. Subsequent changes in the value of impaired loans are included within the provision for loan losses in the same manner in which impairment initially was recognized or as a reduction in the provision that would otherwise be reported. Impaired loans are periodically evaluated to determine if valuation adjustments, or partial write-downs, should be recorded. The need for valuation adjustments arises when observable market prices or current appraised values of collateral indicate a shortfall in collateral value compared to current carrying values of the related loan. If the Company determines that the value of the impaired loan is less than the carrying value of the loan, the Company either establishes an impairment reserve as a specific component of the allowance for loan losses or charges off the impaired amount. These valuation adjustments are considered non-recurring fair value adjustments. REO : The Company records REO (acquired through a lending relationship) at fair value on a non-recurring basis. Fair value adjustments on REO are based on updated real estate appraisals which are based on current market conditions. All REO properties are recorded at the estimated fair value of the real estate, less expected selling costs. From time to time, non-recurring fair value adjustments to REO are recorded to reflect partial write-downs based on an observable market price or current appraised value of property. Banner considers any valuation inputs related to REO to be Level 3 inputs. The individual carrying values of these assets are reviewed for impairment at least annually and any additional impairment charges are expensed to operations.

BANNER CORPORATION (PARENT COMP

BANNER CORPORATION (PARENT COMPANY ONLY)	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
BANNER CORPORATION (PARENT COMPANY ONLY)	BANNER CORPORATION (PARENT COMPANY ONLY) Summary financial information is as follows (in thousands): Statements of Financial Condition December 31 2016 2015 ASSETS Cash $ 86,268 $ 58,232 Investment in trust equities 4,212 4,212 Investment in subsidiaries 1,307,475 1,319,348 Other assets 13,784 21,134 Total assets $ 1,411,739 $ 1,402,926 LIABILITIES AND SHAREHOLDERS’ EQUITY Miscellaneous liabilities $ 8,990 $ 7,846 Deferred tax liability 1,839 2,541 Junior subordinated debentures at fair value 95,200 92,480 Shareholders’ equity 1,305,710 1,300,059 Total liabilities and shareholders' equity $ 1,411,739 $ 1,402,926 Statements of Operations Years Ended December 31 2016 2015 2014 INTEREST INCOME: Interest-bearing deposits $ 127 $ 122 $ 96 OTHER INCOME (EXPENSE): Dividend income from subsidiaries 50,971 170,260 26,027 Equity in undistributed (distributions in excess of) income of subsidiaries 40,852 (116,120 ) 33,612 Other income 60 69 67 Net change in valuation of financial instruments carried at fair value (2,720 ) (2,714 ) (4,073 ) Interest on other borrowings (4,040 ) (3,247 ) (2,914 ) Other expenses (3,450 ) (7,175 ) (2,519 ) Net income before taxes 81,800 41,195 50,296 BENEFIT FROM INCOME TAXES (3,585 ) (4,027 ) (3,774 ) NET INCOME $ 85,385 $ 45,222 $ 54,070 Statements of Cash Flows Years Ended December 31 2016 2015 2014 OPERATING ACTIVITIES: Net income $ 85,385 $ 45,222 $ 54,070 Adjustments to reconcile net income to net cash provided by operating activities: Distributions in excess of (equity in undistributed) income of subsidiaries (40,852 ) 116,120 (33,612 ) Decrease in deferred taxes (702 ) (1,398 ) (1,444 ) Net change in valuation of financial instruments carried at fair value 2,720 2,714 4,073 Decrease (increase) in other assets 7,332 (10,655 ) (3,822 ) Increase in other liabilities 3,233 3,919 222 Net cash provided from operating activities 57,116 155,922 19,487 INVESTING ACTIVITIES: Funds transferred to deferred compensation trust (26 ) (26 ) (26 ) Reduction in investment in subsidiaries 50,000 — — Acquisitions — (132,652 ) — Net cash provided from (used by) investing activities 49,974 (132,678 ) (26 ) FINANCING ACTIVITIES: Issuance of stock for shareholder reinvestment program — 34 127 Repurchase of common stock (50,772 ) — — Cash dividends paid (28,282 ) (17,170 ) (13,462 ) Net cash used by financing activities (79,054 ) (17,136 ) (13,335 ) NET CHANGE IN CASH 28,036 6,108 6,126 CASH, BEGINNING OF PERIOD 58,232 52,124 45,998 CASH, END OF PERIOD $ 86,268 $ 58,232 $ 52,124

STOCK REPURCHASES

STOCK REPURCHASES	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
STOCK REPURCHASE	STOCK REPURCHASES AND RECHARACTERIZATION On April 4, 2016, the Company announced that its Board of Directors had authorized the repurchase of up to 1,711,540 shares of the Company's common stock, or 5% of the Company's outstanding shares. During the year ended December 31, 2016 , the Company adopted a pre-arranged stock trading plan, pursuant to the Board authorization, in accordance with guidelines specified under Rule 10b5-1 of the Securities Exchange Act of 1934. Repurchases under the Company’s 10b5-1 stock trading plan are administered through an independent broker. The stock trading plan will cover the repurchase of up to 1,300,000 shares of the Company’s stock. The stock trading plan will extend through March 12, 2017, unless completed sooner or otherwise extended or terminated. Repurchases are subject to the requirements of the Securities and Exchange Commission, including Rule 10b-18, as well as certain price and other requirements specified in the plan. During the year ended December 31, 2016 , the Company repurchased 1,145,250 common shares under the stock trading plan leaving 566,290 shares available for future repurchase under the Board authorization. In addition to the shares repurchased under the plan there were 25,628 shares surrendered by employees to satisfy tax withholding obligations upon vesting of restricted stock grants. The Company did not repurchase any shares of its common stock during the years ended December 31, 2015 or 2014 except for shares surrendered by employees to satisfy tax withholding obligations upon the vesting of restricted stock grants and shares redeemed relating to the termination of the ESOP. The ESOP was terminated during the year ended December 31, 2014. During the year ended December 31, 2016 , the 1.3 million shares of non-voting common stock issued in connection with the acquisition of Starbuck. and its subsidiary, AmericanWest were sold by the original holder of the shares. These shares contained a provision where they would automatically convert from non-voting to voting upon a permitted transfer of the shares. Therefore, these shares are included in Banner's voting common stock outstanding as of December 31, 2016 .

CALCULATION OF EARNINGS PER COM

CALCULATION OF EARNINGS PER COMMON SHARE	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
CALCULATION OF EARNINGS PER COMMON SHARE	CALCULATION OF EARNINGS PER COMMON SHARE The following tables show the calculation of earnings per common share (in thousands, except per share data): Years Ended December 31 2016 2015 2014 Net income $ 85,385 $ 45,222 $ 54,070 Weighted average number of common shares outstanding Basic 33,820,148 23,801,373 19,359,409 Diluted 33,853,511 23,866,621 19,402,656 Earnings per common share Basic $ 2.52 $ 1.90 $ 2.79 Diluted $ 2.52 $ 1.89 $ 2.79 At December 31, 2016 , 2015 and 2014 there were 290,719 , 231,562 , and 195,106 , respectively, issued but unvested restricted stock shares and units that were included in the computation of diluted earnings per share. At December 31, 2016 and 2015 there were options to purchase an additional 5,000 shares of common stock and at December 31, 2014 there were options to purchase an additional 10,664 shares of common stock that were not included in the computation of diluted earnings per share because their exercise price resulted in them being anti-dilutive. At December 31, 2016, 2015 and 2014 there was a warrant to purchase up to 243,998 shares of common stock and they were not included in the computation of diluted earnings per share because their exercise price resulted in them being anti-dilutive.

SELECTED QUARTERLY FINANCIAL DA

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	12 Months Ended
	Dec. 31, 2016
Selected Quarterly Financial Information [Abstract]
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) Results of operations on a quarterly basis for the years ended December 31, 2016 , 2015 and 2014 were as follows (dollars in thousands except for per share data): Year Ended December 31, 2016 First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 95,301 $ 97,321 $ 97,849 $ 101,007 Interest expense 4,258 4,173 4,141 3,836 Net interest income before provision for loan losses 91,043 93,148 93,708 97,171 Provision for loan losses — 2,000 2,000 2,030 Net interest income 91,043 91,148 91,708 95,141 Non-interest income 19,959 20,537 23,512 19,463 Non-interest expense 84,034 79,887 79,092 79,857 Income before provision for income taxes 26,968 31,798 36,128 34,747 Provision for income taxes 9,194 10,841 12,277 11,943 Net income $ 17,774 $ 20,957 $ 23,851 $ 22,804 Basic earnings per share $ 0.52 $ 0.62 $ 0.70 $ 0.69 Diluted earnings per share 0.52 0.61 0.70 0.69 Dividends declared 0.21 0.21 0.23 0.23 Year Ended December 31, 2015 First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 49,069 $ 54,076 $ 54,793 $ 96,495 Interest expense 2,533 2,619 2,605 4,396 Net interest income before provision for loan losses 46,536 51,457 52,188 92,099 Provision for loan losses — — — — Net interest income 46,536 51,457 52,188 92,099 Non-interest income 13,696 16,141 14,098 18,356 Non-interest expense 41,914 47,734 46,697 100,254 Income before provision for income taxes 18,318 19,864 19,589 10,201 Provision for income taxes 6,184 6,615 6,642 3,308 Net income $ 12,134 $ 13,249 $ 12,947 $ 6,893 Basic earnings per share $ 0.61 $ 0.64 $ 0.62 $ 0.20 Diluted earnings per share 0.61 0.64 0.62 0.20 Dividends declared 0.18 0.18 0.18 0.18 Year Ended December 31, 2014 First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 45,106 $ 46,540 $ 49,764 $ 49,251 Interest expense 2,767 2,732 2,700 2,590 Net interest income before provision for loan losses 42,339 43,808 47,064 46,661 Provision for loan losses — — — — Net interest income 42,339 43,808 47,064 46,661 Non-interest income 9,032 20,310 13,536 12,113 Non-interest expense 35,581 38,435 38,495 41,230 Income before provision for income taxes 15,790 25,683 22,105 17,544 Provision for income taxes 5,241 8,696 7,284 5,831 Net income $ 10,549 $ 16,987 $ 14,821 $ 11,713 Basic earnings per share $ 0.55 $ 0.88 $ 0.76 $ 0.60 Diluted earnings per share 0.54 0.88 0.76 0.60 Dividends declared 0.18 0.18 0.18 0.18

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	Lease Commitments—The Company leases 108 buildings and offices under non-cancelable operating leases. The leases contain various provisions for increases in rental rates, based either on changes in the published Consumer Price Index or a predetermined escalation schedule. Substantially all of the leases provide the Company with the option to extend the lease term one or more times following expiration of the initial term. Financial Instruments with Off-Balance Sheet Risk—The Company has financial instruments with off-balance-sheet risk generated in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit, commitments related to standby letters of credit, commitments to originate loans, commitments to sell loans, and commitments to buy or sell securities. These instruments involve, to varying degrees, elements of credit and interest rate risk similar to the risk involved in on-balance sheet items recognized in our Consolidated Statements of Financial Condition. Our exposure to credit loss in the event of nonperformance by the other party to the financial instrument from commitments to extend credit and standby letters of credit is represented by the contractual notional amount of those instruments. We use the same credit policies in making commitments and conditional obligations as for on-balance sheet instruments. Outstanding commitments for which no asset or liability for the notional amount has been recorded consisted of the following at the dates indicated (in thousands): Contract or Notional Amount December 31, 2016 December 31, 2015 Commitments to extend credit $ 2,204,795 $ 2,132,996 Standby letters of credit and financial guarantees 17,694 22,315 Commitments to originate loans 69,833 32,908 Risk participation agreement 7,488 7,672 Derivatives also included in Note 24: Commitments to originate loans held for sale 69,487 76,146 Commitments to sell loans secured by one- to four-family residential properties 36,907 37,545 Commitments to sell securities related to mortgage banking activities 44,000 41,500 Commitments to extend credit are agreements to lend to a customer, as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Many of the commitments may expire without being drawn upon; therefore, the total commitment amounts do not necessarily represent future cash requirements. Each customer’s creditworthiness is evaluated on a case-by-case basis. The amount of collateral obtained, if deemed necessary upon extension of credit, is based on management’s credit evaluation of the customer. Collateral held varies, but may include accounts receivable, inventory, property, plant and equipment, and income producing commercial properties. The Company's reserve for unfunded loan commitments was $3.6 million and $3.9 million , at December 31, 2016 and 2015 , respectively. Standby letters of credit are conditional commitments issued to guarantee a customer’s performance or payment to a third party. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. Through the acquisition of Starbuck, Banner Bank assumed a risk participation agreement. Under the risk participation agreement, Banner Bank guarantees the financial performance of a borrower on the participated portion of a interest rate swap on a loan. Interest rates on residential one- to four-family mortgage loan applications are typically rate locked (committed) to customers during the application stage for periods ranging from 30 to 60 days, the most typical period being 45 days. Traditionally, these loan applications with rate lock commitments had the pricing for the sale of these loans locked with various qualified investors under a best-efforts delivery program at or near the time the interest rate is locked with the customer. The Bank then attempts to deliver these loans before their rate locks expired. This arrangement generally required delivery of the loans prior to the expiration of the rate lock. Delays in funding the loans would require a lock extension. The cost of a lock extension at times was borne by the customer and at times by the Bank. These lock extension costs have not had a material impact to our operations. For mandatory delivery commitments the Company enters into forward commitments at specific prices and settlement dates to deliver either: (1) residential mortgage loans for purchase by secondary market investors (i.e., Freddie Mac or Fannie Mae), or (2) mortgage-backed securities to broker/dealers. The purpose of these forward commitments is to offset the movement in interest rates between the execution of its residential mortgage rate lock commitments with borrowers and the sale of those loans to the secondary market investor. There were no counterparty default losses on forward contracts during 2016 or 2015 . Market risk with respect to forward contracts arises principally from changes in the value of contractual positions due to changes in interest rates. The Company limits its exposure to market risk by monitoring differences between commitments to customers and forward contracts with market investors and securities broker/dealers. In the event the Company has forward delivery contract commitments in excess of available mortgage loans, the transaction is completed by either paying or receiving a fee to or from the investor or broker/dealer equal to the increase or decrease in the market value of the forward contract. Changes in the value of rate lock commitments are recorded as assets and liabilities as explained in Note 1: “Derivative Instruments.” In the normal course of business, the Company and/or its subsidiaries have various legal proceedings and other contingent matters outstanding. These proceedings and the associated legal claims are often contested and the outcome of individual matters is not always predictable. These claims and counter-claims typically arise during the course of collection efforts on problem loans or with respect to action to enforce liens on properties in which the Banks hold a security interest. Based upon the information known to management at this time, the Company and the Banks are not a party to any legal proceedings that management believes would have a material adverse effect on the results of operations or consolidated financial position at December 31, 2016 . In connection with certain asset sales, the Banks typically make representations and warranties about the underlying assets conforming to specified guidelines. If the underlying assets do not conform to the specifications, the Bank may have an obligation to repurchase the assets or indemnify the purchaser against any loss. The Banks believe that the potential for material loss under these arrangements is remote. Accordingly, the fair value of such obligations is not material.

DERIVATIVES AND HEDGING DERIVAT

DERIVATIVES AND HEDGING DERIVATIVES AND HEDGING	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVES AND HEDGING	DERIVATIVES AND HEDGING The Company, through its Banner Bank subsidiary, is party to various derivative instruments that are used for asset and liability management and customer financing needs. Derivative instruments are contracts between two or more parties that have a notional amount and an underlying variable, require no net investment and allow for the net settlement of positions. The notional amount serves as the basis for the payment provision of the contract and takes the form of units, such as shares or dollars. The underlying variable represents a specified interest rate, index, or other component. The interaction between the notional amount and the underlying variable determines the number of units to be exchanged between the parties and influences the market value of the derivative contract. The Company obtains dealer quotations to value its derivative contracts. The Company's predominant derivative and hedging activities involve interest rate swaps related to certain term loans and forward sales contracts associated with mortgage banking activities. Generally, these instruments help the Company manage exposure to market risk and meet customer financing needs. Market risk represents the possibility that economic value or net interest income will be adversely affected by fluctuations in external factors such as market-driven interest rates and prices or other economic factors. Derivatives Designated in Hedge Relationships The Company's fixed rate loans result in exposure to losses in value or net interest income as interest rates change. The risk management objective for hedging fixed rate loans is to effectively convert the fixed rate received to a floating rate. The Company has hedged exposure to changes in the fair value of certain fixed rate loans through the use of interest rate swaps. For a qualifying fair value hedge, changes in the value of the derivatives are recognized in current period earnings along with the corresponding changes in the fair value of the designated hedged item attributable to the risk being hedged. Under a prior program, customers received fixed interest rate commercial loans and the Banner Bank subsequently hedged that fixed rate loan by entering into an interest rate swap with a dealer counterparty. Banner Bank receives fixed rate payments from the customers on the loans and makes similar fixed rate payments to the dealer counterparty on the swaps in exchange for variable rate payments based on the one-month LIBOR index. Some of these interest rate swaps are designated as fair value hedges. Through application of the “short cut method of accounting,” there is an assumption that the hedges are effective. The Bank discontinued originating interest rate swaps under this program in 2008. As of December 31, 2016 and December 31, 2015 , the notional values or contractual amounts and fair values of the Company's derivatives designated in hedge relationships were as follows (in thousands): Asset Derivatives Liability Derivatives December 31, 2016 December 31, 2015 December 31, 2016 December 31, 2015 Notional/ Contract Amount Fair Value (1) Notional/ Contract Amount Fair Value (1) Notional/ Contract Amount Fair Value (2) Notional/ Contract Amount Fair Value (2) Interest rate swaps $ 5,855 $ 660 $ 6,734 $ 938 $ 5,855 $ 660 $ 6,734 $ 938 (1) Included in Loans Receivable on the Consolidated Statements of Financial Condition. (2) Included in Other Liabilities on the Consolidated Statements of Financial Condition. Derivatives Not Designated in Hedge Relationships Interest Rate Swaps: Banner Bank uses an interest rate swap program for commercial loan customers, that provides the client with a variable rate loan and enters into an interest rate swap in which the client receives a variable rate payment in exchange for a fixed rate payment. The Bank offsets its risk exposure by entering into an offsetting interest rate swap with a dealer counterparty for the same notional amount and length of term as the client interest rate swap providing the dealer counterparty with a fixed rate payment in exchange for a variable rate payment. These swaps do not qualify as designated hedges; therefore, each swap is accounted for as a free standing derivative. Mortgage Banking: In the normal course of business, the Company sells originated mortgage loans into the secondary mortgage loan markets. During the period of loan origination and prior to the sale of the loans in the secondary market, the Company has exposure to movements in interest rates associated with written interest rate lock commitments with potential borrowers to originate loans that are intended to be sold and for closed mortgage loans held for sale that are awaiting sale and delivery into the secondary market. The Company economically hedges the risk of changing interest rates associated with these mortgage loan commitments by entering into forward sales contracts to sell residential mortgage loans or mortgage-backed securities to broker/dealers as specific prices and dates. As of December 31, 2016 and December 31, 2015 , the notional values or contractual amounts and fair values of the Company's derivatives not designated in hedge relationships were as follows (in thousands): Asset Derivatives Liability Derivatives December 31, 2016 December 31, 2015 December 31, 2016 December 31, 2015 Notional/ Contract Amount Fair Value (1) Notional/ Contract Amount Fair Value (1) Notional/ Contract Amount Fair Value (2) Notional/ Contract Amount Fair Value (2) Interest rate swaps $ 309,936 $ 7,670 $ 293,937 $ 11,046 $ 309,936 $ 7,670 $ 293,937 $ 11,046 Mortgage loan commitments 42,296 30 76,146 428 27,191 174 — — Forward sales contracts 71,192 452 41,500 43 9,715 115 32,763 50 $ 423,424 $ 8,152 $ 411,583 $ 11,517 $ 346,842 $ 7,959 $ 326,700 $ 11,096 (1) Included in Other Assets on the Consolidated Statements of Financial Condition, with the exception of those interest rate swaps from prior to 2009 that were not designated in hedge relationships (with a fair value of $822,000 at December 31, 2016 and $327,000 at December 31, 2015 ), which are included in Loans Receivable. (2) Included in Other Liabilities on the Consolidated Statements of Financial Condition. Gains (losses) recognized in income on non-designated hedging instruments for the years ended December 31, 2016 and 2015 were as follows (in thousands): For the Year Ended December 31, Location on Income Statement 2016 2015 Mortgage loan commitments Mortgage banking operations $ (348 ) $ 100 Forward sales contracts Mortgage banking operations 296 141 $ (52 ) $ 241 The Company is exposed to credit-related losses in the event of nonperformance by the counterparty to these agreements. Credit risk of the financial contract is controlled through the credit approval, limits, and monitoring procedures and management does not expect the counterparties to fail their obligations. In connection with the interest rate swaps between Banner Bank and the dealer counterparties, the agreements contain a provision where if Banner Bank fails to maintain its status as a well/adequately capitalized institution, then the counterparty could terminate the derivative positions and Banner Bank would be required to settle its obligations. Similarly, Banner Bank could be required to settle its obligations under certain of its agreements if specific regulatory events occur, such as a publicly issued prompt corrective action directive, cease and desist order, or a capital maintenance agreement that required Banner Bank to maintain a specific capital level. If Banner Bank had breached any of these provisions at December 31, 2016 or December 31, 2015 , it could have been required to settle its obligations under the agreements at the termination value. As of December 31, 2016 and 2015 , the termination value of derivatives in a net liability position related to these agreements was $7.6 million and $12.0 million , respectively. The Company generally posts collateral against derivative liabilities in the form of government agency-issued bonds, mortgage-backed securities, or commercial mortgage-backed securities. Collateral posted against derivative liabilities was $29.3 million and $20.8 million as of December 31, 2016 and 2015 , respectively. Derivative assets and liabilities are recorded at fair value on the balance sheet and do not take into account the effects of master netting agreements. Master netting agreements allow the Company to settle all derivative contracts held with a single counterparty on a net basis and to offset net derivative positions with related collateral where applicable. The following table illustrates the potential effect of the Company's derivative master netting arrangements, by type of financial instrument, on the Company's Consolidated Statements of Financial Condition as of December 31, 2016 and December 31, 2015 (in thousands): December 31, 2016 Gross Amounts of Financial Instruments Not Offset in the Statement of Financial Condition Gross Amounts Recognized Amounts offset in the Statement of Financial Condition Net Amounts in the Statement of Financial Condition Netting Adjustment Per Applicable Master Netting Agreements Fair Value of Financial Collateral in the Statement of Financial Condition Net Amount Derivative assets Interest rate swaps $ 8,330 $ — $ 8,330 $ (362 ) $ — $ 7,968 $ 8,330 $ — $ 8,330 $ (362 ) $ — $ 7,968 Derivative liabilities Interest rate swaps $ 8,330 $ — $ 8,330 $ (362 ) $ (7,557 ) $ 411 $ 8,330 $ — $ 8,330 $ (362 ) $ (7,557 ) $ 411 December 31, 2015 Gross Amounts of Financial Instruments Not Offset in the Statement of Financial Condition Gross Amounts Recognized Amounts offset in the Statement of Financial Condition Net Amounts in the Statement of Financial Condition Netting Adjustment Per Applicable Master Netting Agreements Fair Value of Financial Collateral in the Statement of Financial Condition Net Amount Derivative assets Interest rate swaps $ 11,984 $ — $ 11,984 $ — $ — $ 11,984 $ 11,984 $ — $ 11,984 $ — $ — $ 11,984 Derivative liabilities Interest rate swaps $ 11,984 $ — $ 11,984 $ — $ (11,984 ) $ — $ 11,984 $ — $ 11,984 $ — $ (11,984 ) $ —

BASIS OF PRESENTATION AND SUM33

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles of Consolidation	Principles of Consolidation: The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All material intercompany transactions, profits and balances have been eliminated. The consolidated financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States (GAAP) and under the rules and regulations of the U.S. Securities and Exchange Commission (the SEC).
Subsequent Events	Subsequent Events: The Company has evaluated events and transactions subsequent to December 31, 2016 for potential recognition or disclosure.
Cash and Cash Equivalents, Policy	Cash and Cash Equivalents: Cash and cash equivalents include cash and due from banks and temporary investments which are federal funds sold and interest bearing balances due from other banks. Cash and cash equivalents generally have maturities of three months or less at the date of purchase.
Business Combinations	Business Combinations: Business combinations are accounted for using the acquisition method of accounting and, accordingly, assets acquired and liabilities assumed, both tangible and intangible, and consideration exchanged are recorded at acquisition date fair values. The excess purchase consideration over fair value of net assets acquired is recorded as goodwill. In the event that the fair value of net assets acquired exceeds the purchase price, including fair value of liabilities assumed, a bargain purchase gain is recorded on that acquisition. Expenses incurred in connection with a business combination are expensed as incurred. Changes in deferred tax asset valuation allowances related to acquired tax uncertainties are recognized in net income after the measurement period.
Use of Estimates	Use of Estimates: In the opinion of management, the accompanying consolidated statements of financial condition and related consolidated statements of operations, comprehensive income, changes in shareholders’ equity and cash flows reflect all adjustments (which include reclassification and normal recurring adjustments) that are necessary for a fair presentation in conformity with GAAP. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect amounts reported in the financial statements. Various elements of the Company’s accounting policies, by their nature, are inherently subject to estimation techniques, valuation assumptions and other subjective assessments. In particular, management has identified several accounting policies that, due to the judgments, estimates and assumptions inherent in those policies, are critical to an understanding of Banner’s financial statements. These policies relate to (i) the methodology for the recognition of interest income, (ii) determination of the provision and allowance for loan and lease losses, (iii) the valuation of financial assets and liabilities recorded at fair value, including other-than-temporary impairment (OTTI) losses, (iv) the valuation of intangibles, such as goodwill, core deposit intangibles (CDI) and mortgage servicing rights, (v) the valuation of real estate held for sale, (vi) the valuation or recognition of deferred tax assets and liabilities and (vii) the valuation of assets and liabilities acquired in business combinations and subsequent recognition of related income and expense. These policies and judgments, estimates and assumptions are described in greater detail in subsequent Notes to the Consolidated Financial Statements. Management believes that the judgments, estimates and assumptions used in the preparation of the financial statements are appropriate based on the factual circumstances at the time. However, given the sensitivity of the financial statements to these critical accounting policies, the use of other judgments, estimates and assumptions could result in material differences in the Company’s results of operations or financial condition. Further, subsequent changes in economic or market conditions could have a material impact on these estimates and the Company’s financial condition and operating results in future periods.
Securities	Securities: Securities are classified as held-to-maturity when the Company has the ability and positive intent to hold them to maturity. Securities classified as available-for-sale are available for future liquidity requirements and may be sold prior to maturity. Securities classified as trading are also available for future liquidity requirements and may be sold prior to maturity. Purchase premiums and discounts are recognized in interest income using the interest method over the terms of the securities. Securities classified as held-to-maturity are carried at cost, adjusted for amortization of premiums and accretion of discounts to maturity and, if appropriate, any other-than-temporary impairment losses. Securities classified as available-for-sale are recorded at fair value. Unrealized holding gains and losses on securities classified as available-for-sale are excluded from earnings and are reported net of tax as accumulated other comprehensive income (OCI), a component of shareholders’ equity, until realized. Securities classified as trading are also recorded at fair value. Unrealized holding gains and losses on securities classified as trading are included in earnings. (See Note 18 for a more complete discussion of accounting for the fair value of financial instruments.) Declines in the fair value of securities below their cost that are deemed to be other-than-temporary are recognized in earnings as realized losses. Realized gains and losses on sale are computed on the specific identification method and are included in earnings on the trade date sold. The Company reviews investment securities on an ongoing basis for the presence of OTTI or permanent impairment, taking into consideration current market conditions, fair value in relationship to cost, extent and nature of the change in fair value, issuer rating changes and trends, whether the Company intends to sell a security or if it is likely that it will be required to sell the security before recovery of the amortized cost basis of the investment, which may be maturity, and other factors. For debt securities, if the Company intends to sell the security or it is likely that the Company will be required to sell the security before recovering its cost basis, the entire impairment loss would be recognized in earnings as an OTTI. If the Company does not intend to sell the security and it is not likely that the Company will be required to sell the security but the Company does not expect to recover the entire amortized cost basis of the security, only the portion of the impairment loss representing credit losses would be recognized in earnings. The credit loss on a security is measured as the difference between the amortized cost basis and the present value of the cash flows expected to be collected. Projected cash flows are discounted by the original or current effective interest rate depending on the nature of the security being measured for potential OTTI. The remaining impairment related to all other factors, the difference between the present value of the cash flows expected to be collected and fair value, is recognized as a charge to OCI. Impairment losses related to all other factors are presented as separate categories within OCI. For investment securities transferred from held-to-maturity to available-for-sale, unrealized gains or losses from the time of transfer are accreted or amortized over the remaining life of the debt security based on the amount and timing of future estimated cash flows. The accretion or amortization of the amount recorded in OCI increases the carrying value of the investment and does not affect earnings.
Investment in FHLB Stock	Investment in FHLB Stock: At December 31, 2016 , the Banks had $12.5 million in FHLB of Des Moines stock (FHLB stock), compared to $16.1 million at December 31, 2015 . The Banks' investments in FHLB stock are generally viewed as a long-term investment and are carried at par value ( $100 per share), which reasonably approximates its fair value. FHLB stock does not have a readily determinable fair value. Ownership of FHLB stock is restricted to the FHLB and member institutions and can only be purchased and redeemed at par. As members of the FHLB system, the Banks are required to maintain a minimum level of investment in FHLB stock based on specific percentages of their outstanding FHLB advances. Management periodically evaluates FHLB stock for impairment. Management's determination of whether these investments are impaired is based on its assessment of the ultimate recoverability of cost rather than by recognizing temporary declines in value. The determination of whether a decline affects the ultimate recoverability of cost is influenced by criteria such as (1) the significance of any decline in net assets of the FHLB as compared to the capital stock amount for the FHLB and the length of time this situation has persisted, (2) commitments by the FHLB to make payments required by law or regulation and the level of such payments in relation to the operating performance of the FHLB, (3) the impact of legislative and regulatory changes on institutions and, accordingly, the customer base of the FHLB, and (4) the liquidity position of the FHLB. The Company has determined there is no impairment on the FHLB stock investment as of December 31, 2016 .
Loans Receivable	Loans Receivable: The Banks originate residential one- to four-family and multifamily mortgage loans for both portfolio investment and sale in the secondary market. The Banks also originate construction and land development, commercial real estate, commercial business, agricultural and consumer loans for portfolio investment. Loans receivable not designated as held for sale are recorded at the principal amount outstanding, net of allowance for loan losses, deferred fees, discounts and premiums. Premiums, discounts and deferred loan fees are amortized to maturity using the level-yield methodology. Some of the Company’s loans are reported as troubled debt restructures (TDRs). Loans are appropriately reported as TDRs when the Banks grant a concession(s) to a borrower experiencing financial difficulties that it would not otherwise consider. Examples of such concessions include forgiveness of principal or accrued interest, extending the maturity date(s) or providing a lower interest rate than would be normally available for a transaction of similar risk. As a result of these concessions, loans identified as TDRs are impaired as the Bank will not collect all amounts due, both principal and interest, in accordance with the terms of the original loan agreement. TDRs are accounted for in accordance with the Banks’ impaired loan accounting policies.
Finance, Loan and Lease Receivables, Held-for-sale	Loans Held for Sale . Residential one- to four-family and multifamily mortgage loans with the intent to be sold in the secondary market are considered held for sale. Residential one- to four-family loans under best effort delivery commitments and multifamily mortgage loans are carried at the lower of aggregate cost or estimated market value. Residential one- to four-family loans under mandatory delivery commitments are carried at fair value in order to match changes in the value of the loans with the value of the economic hedges on the loans. Fair values for residential mortgage loans held for sale are determined by comparing actual loan rates to current secondary market prices for similar loans. Fair values for multifamily loans held for sale are calculated using recent sales data for comparable loans. Net unrealized losses on loans held for sale are recognized through a valuation allowance by charges to income. Non-refundable fees and direct loan origination costs related to loans held for sale are recognized as part of the cost basis of the loan. Gains and losses on sales of loans held for sale are determined using the specific identification method and are recorded in the mortgage banking operations component of non-interest income .
Acquired Loans Policy	Acquired Loans: Purchased loans, including loans acquired in business combinations, are recorded at their fair value at the acquisition date. Credit discounts are included in the determination of fair value; therefore, an allowance for loan and lease losses is not recorded at the acquisition date. Acquired loans are evaluated upon acquisition and classified as either purchased credit-impaired or purchased non-credit-impaired. Purchased credit-impaired (PCI) loans reflect credit deterioration since origination such that it is probable at acquisition that the Company will be unable to collect all contractually required payments. The excess of the cash flows expected to be collected over a PCI pool's carrying value is considered to be the accretable yield and is recognized as interest income over the estimated life of the pool using the effective yield method. The excess of the undiscounted contractual balances due over the cash flows expected to be collected is considered to be the nonaccretable difference. The nonaccretable difference represents the Company's estimate of the credit losses expected to occur and was considered in determining the fair value of the loans as of the acquisition date. Subsequent to the acquisition date, any increases in expected cash flows over those expected at purchase date in excess of fair value are adjusted through a change to the accretable yield on a prospective basis. Any subsequent decreases in expected cash flows attributable to credit deterioration are recognized by recording a provision for loan losses. For purchased non-credit-impaired loans, the difference between the fair value and unpaid principal balance of the loan at the acquisition date is amortized or accreted to interest income over the life of the loans. Any subsequent deterioration in credit quality is recognized by recording a provision for loan losses.
Income Recognition on Nonaccrual and Impaired Loans	Income Recognition on Nonaccrual and Impaired Loans and Securities: Interest on loans and securities is accrued as earned unless management doubts the collectability of the asset or the unpaid interest. Interest accruals on loans are generally discontinued when loans become 90 days past due for payment of interest or principal and the loans are then placed on nonaccrual status. All previously accrued but uncollected interest is deducted from interest income upon transfer to nonaccrual status. For any future payments collected, interest income is recognized only upon management’s assessment that there is a strong likelihood that the full amount of a loan will be repaid or recovered. A loan may be put on nonaccrual status sooner than this policy would dictate if, in management’s judgment, the interest may be uncollectable. While less common, similar interest reversal and nonaccrual treatment is applied to investment securities if their ultimate collectability becomes questionable.
Provision and Allowance for Loan Losses	Provision and Allowance for Loan Losses: The provision for loan losses reflects the amount required to maintain the allowance for losses at an appropriate level based upon management’s evaluation of the adequacy of general and specific loss reserves. The Company maintains an allowance for loan losses consistent in all material respects with GAAP. The Company has established systematic methodologies for the determination of the adequacy of the Company’s allowance for loan losses. The methodologies are set forth in a formal policy and take into consideration the need for a general valuation allowance as well as specific allowances that are tied to individual problem loans. The Company increases its allowance for loan losses by charging provisions for probable loan losses against its income and values impaired loans consistent with accounting guidelines. The allowance for loan losses is maintained at a level sufficient to provide for estimated losses based on evaluating known and inherent risks in the loan portfolio and upon the Company’s continuing analysis of the factors underlying the quality of the loan portfolio. These factors include, among others, changes in the size and composition of the loan portfolio, delinquency rates, actual loan loss experience, current economic conditions, detailed analysis of individual loans for which full collectability may not be assured, and determination of the existence and realizable value of the collateral and guarantees securing the loans. Realized losses related to specific assets are applied as a reduction of the carrying value of the assets and charged immediately against the allowance for loan loss reserve. Recoveries on previously charged off loans are credited to the allowance for loan losses. The reserve is based upon factors and trends identified by Banner at the time financial statements are prepared. Although the Company uses the best information available, future adjustments to the allowance for loan losses may be necessary due to economic, operating, regulatory and other conditions beyond the Company’s control. The adequacy of general and specific reserves is based on a continuing evaluation of the pertinent factors underlying the quality of the loan portfolio as well as individual review of certain large balance loans. Large groups of smaller-balance homogeneous loans are collectively evaluated for impairment. Loans that are collectively evaluated for impairment include residential real estate and consumer loans and, as appropriate, smaller balance non-homogeneous loans. Larger balance non-homogeneous residential construction and land, commercial real estate, commercial business loans and unsecured loans are individually evaluated for impairment. Loans are considered impaired when, based on current information and events, the Company determines that it is probable that it will be unable to collect all amounts due according to the contractual terms of the loan agreement. Factors involved in determining impairment include, but are not limited to, the financial condition of the borrower and the value of the underlying collateral. Impaired loans are measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate or, as a practical expedient, at the loan’s observable market price, or if the loan is collateral dependent, at the fair value of collateral less selling costs. Subsequent changes in the value of impaired loans are included within the provision for loan losses in the same manner in which impairment initially was recognized or as a reduction in the provision that would otherwise be reported. The Company’s methodology for assessing the appropriateness of the allowance for loan losses consists of several key elements, which include specific allowances, an allocated formula allowance and an unallocated allowance. Losses on specific loans are provided for when the losses are probable and estimable. General loan loss reserves are established to provide for inherent loan portfolio risks not specifically provided for. The level of general reserves is based on analysis of potential exposures existing in the loan portfolio including evaluation of historical trends, current market conditions and other relevant factors identified by us at the time the financial statements are prepared. The formula allowance is calculated by applying loss factors to outstanding loans, excluding those loans that are subject to individual analysis for specific allowances. Loss factors are based on the Company’s historical loss experience adjusted for significant environmental considerations, including the experience of other banking organizations, which in the judgment of management affects the collectability of the loan portfolio as of the evaluation date. The unallocated allowance is based upon the Company’s evaluation of various factors that are not directly measured in the determination of the formula and specific allowances. While the Company believes the estimates and assumptions used in the determination of the adequacy of the allowance for loan losses are reasonable, there can be no assurance that such estimates and assumptions will not be proved incorrect in the future, or that the actual amount of future provisions will not exceed the amount of past provisions or that any increased provisions that may be required will not adversely impact the financial condition and results of operations of the Company. In addition, the determination of the amount of the allowance for loan losses is subject to review by bank regulators as part of the routine examination process, which may result in the adjustment of reserves based upon their judgment of information available to them at the time of their examination.
Loan Origination and Commitment Fees	Loan Origination and Commitment Fees: Loan origination fees, net of certain specifically defined direct loan origination costs, are deferred and recognized as an adjustment of the loans’ interest yield using the level-yield method over the contractual term of each loan adjusted for actual loan prepayment experience. Net deferred fees or costs related to loans held for sale are recognized as part of the cost basis of the loan. Loan commitment fees are deferred until the expiration of the commitment period unless management believes there is a remote likelihood that the underlying commitment will be exercised, in which case the fees are amortized to fee income using the straight-line method over the commitment period. If a loan commitment is exercised, the deferred commitment fee is accounted for in the same manner as a loan origination fee. Deferred commitment fees associated with expired commitments are recognized as fee income.
Real Estate Held for Sale	Real Estate Owned: Property acquired by foreclosure or deed in lieu of foreclosure is initially recorded at the estimated fair value of the property, less expected selling costs. Development and improvement costs relating to the property are capitalized while direct holding costs are expensed. The carrying value of the property is periodically evaluated by management and, if necessary, allowances are established to reduce the carrying value to net realizable value. Gains or losses at the time the property is sold are charged or credited to operations in the period in which they are realized. The amounts the Banks will ultimately recover from real estate held for sale may differ substantially from the carrying value of the assets because of market factors beyond the Banks’ control or because of changes in the Banks’ strategies for recovering the investment.
Schedule of Property and Equipment Useful Lives	The provision for depreciation is based upon the straight-line method applied to individual assets and groups of assets acquired in the same year over the lesser of their estimated useful lives or the related lease terms of the assets: Buildings and leased improvements 10–39 years Furniture and equipment 3 – 10 years
Property and Equipment	Property and Equipment: Property and equipment is carried at cost less accumulated depreciation. The provision for depreciation is based upon the straight-line method applied to individual assets and groups of assets acquired in the same year over the lesser of their estimated useful lives or the related lease terms of the assets: Buildings and leased improvements 10–39 years Furniture and equipment 3 – 10 years Routine maintenance, repairs and replacement costs are expensed as incurred. Expenditures which significantly increase values or extend useful lives are capitalized. The Company reviews buildings, leasehold improvements and equipment for impairment whenever events or changes in circumstances indicate that the undiscounted cash flows for the property are less than its carrying value. If identified, an impairment loss is recognized through a charge to earnings based on the fair value of the property.
Goodwill and Intangible Assets, Goodwill, Policy	Goodwill: Goodwill represents the excess of the purchase consideration over the fair value of the assets acquired, net of the fair values of liabilities assumed in a business combination and is not amortized but is reviewed annually, or more frequently as current circumstances and conditions warrant, for impairment. An assessment of qualitative factors is completed to determine if it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the qualitative analysis concludes that further analysis is required, then a quantitative impairment test would be completed. The quantitative goodwill impairment test is a two-step process. The first step compares the reporting unit's estimated fair values, including goodwill, to its carrying amount. If the carrying amount exceeds its fair value, then goodwill impairment may be indicated. The second step allocates the reporting units fair value to its assets and liabilities. If the unallocated fair value does not exceed the carrying amount of goodwill then an impairment loss would be recognized as a charge to earnings.
Other Intangible Assets	Other Intangible Assets: Other intangible assets consist primarily of core deposit intangibles (CDI), which are amounts recorded in business combinations or deposit purchase transactions related to the value of transaction-related deposits and the value of the customer relationships associated with the deposits. CDI is being amortized on an accelerated basis over a weighted average estimated useful life of three to ten years. These assets are reviewed at least annually for events or circumstances that could impact their recoverability. These events could include loss of the underlying core deposits, increased competition or adverse changes in the economy. To the extent other identifiable intangible assets are deemed unrecoverable, impairment losses are recorded in other non-interest expense to reduce the carrying amount of the assets. Other intangibles also include favorable leasehold intangibles (LHI). LHI represents the value assigned to leases assumed in an acquisition in which the lease terms are favorable compared to a market lease at the date of acquisition. LHI is amortized over the underlying lease term and is reviewed at least annually for events or circumstances that could impair the value.
Mortgage Servicing Rights	Mortgage Servicing Rights: Servicing assets are recognized as separate assets when rights are acquired through purchase or sale of loans. Generally, purchased servicing rights are capitalized at the cost to acquire the rights. For sales of mortgage loans, the value of the servicing right is estimated and capitalized. Fair values are estimated based on an independent dealer analysis of discounted cash flows. Capitalized servicing rights are reported in other assets and are amortized into non-interest income in proportion to, and over the period of, the estimated future net servicing income of the underlying financial assets. Servicing assets are evaluated for impairment based upon the fair value of the rights as compared to amortized cost. Impairment is determined by stratifying rights into tranches based on predominant risk characteristics for the underlying loans, such as interest rate, balance outstanding, loan type, age and remaining term, and investor type. Impairment is recognized through a valuation allowance for an individual tranche, to the extent that fair value is less than the capitalized amount for the tranche. If the Company later determines that all or a portion of the impairment no longer exists for a particular tranche, a reduction of the allowance may be recorded as an increase to income. Servicing fee income is recorded for fees earned for servicing loans and is reflected in mortgage banking operations on the Consolidated Statements of Operations. The fees are based on a contractual percentage of the outstanding principal or a fixed amount per loan and are recorded as income when earned. The amortization of mortgage servicing rights is netted against loan servicing fee income.
Bank-Owned Life Insurance (BOLI)	Bank-Owned Life Insurance (BOLI): The Banks have purchased, or acquired through mergers, life insurance policies in connection with the implementation of certain executive supplemental income, salary continuation and deferred compensation retirement plans. These policies provide protection against the adverse financial effects that could result from the death of a key employee and provide tax-exempt income to offset expenses associated with the plans. It is the Banks’ intent to hold these policies as a long-term investment; however, there may be an income tax impact if the Bank chooses to surrender certain policies. Although the lives of individual current or former management-level employees are insured, the Banks are the respective owners and sole or partial beneficiaries.
Derivative Instruments	Derivative Instruments: Derivatives include “off-balance-sheet” financial products, the value of which is dependent on the value of underlying financial assets, such as stock, bonds, foreign currency, or a reference rate or index. Such derivatives include “forwards,” “futures,” “options” or “swaps.” Banner Bank is a party to $8.7 million in notional amounts of interest rate swaps at December 31, 2016 . Some of these swaps serve as hedges to an equal amount of fixed rate loans which include market value prepayment penalties that mirror the provision of the specifically matched interest rate swaps. In addition, Banner Bank uses an interest rate swap program for commercial loan customers that provides the client with a variable rate loan and enters into an interest rate swap allowing them to effectively fix their loan interest rates. These customer swaps are matched with third party swaps with qualified broker/dealer or banks to offset the risk. At December 31, 2016 , Banner Bank had $307.1 million in notional amounts of these customer interest rate swaps outstanding, with an equal amount of offsetting third party swaps also in place. The fair value adjustments for these swaps are reflected in other assets or other liabilities as appropriate. Further, as a part of its mortgage banking activities, the Company issues “rate lock” commitments to borrowers and obtains offsetting “best efforts” delivery commitments from purchasers of loans. The Company also uses forward contracts for the sale of mortgage-backed securities and mandatory delivery commitments for the sale of loans to hedge "rate lock" commitments and loans held for sale. The commitments to originate mortgage loans held for sale and the related delivery contracts are considered derivatives. The Company recognizes all derivatives as either assets or liabilities in the balance sheet and requires measurement of those instruments at fair value through adjustments to current earnings. None of these residential mortgage loan related derivatives are designated as hedging instruments for accounting purposes. Rather, they are accounted for as free-standing derivatives, or economic hedges, and the Company reports changes in fair values of its derivatives in current period net income. The fair values for these instruments, which generally change as a result of changes in the level of market interest rates, are estimated based on dealer quotes and secondary market sources. Assumptions used include rate assumptions based on historical information, current mortgage interest rates, the stage of completion of the underlying application and underwriting process, the time remaining until the expiration of the derivative loan commitment, and the expected net future cash flows related to the associated servicing of the loan (see Note 24 for a more complete discussion of derivatives and hedging).
Transfers of Financial Assets	Transfers of Financial Assets: Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Banks, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (3) the Banks do not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity.
Advertising Expenses	Advertising Expenses: Advertising costs are expensed as incurred. Costs related to production of advertising are considered incurred when the advertising is first used.
Income Taxes	Income Taxes: The Company files a consolidated income tax return including all of its wholly-owned subsidiaries on a calendar year basis. 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 will 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 of change. A valuation allowance is recognized as a reduction to deferred tax assets when management determines it is more likely than not that deferred tax assets will not be available to offset future income tax liabilities. Accounting standards for income taxes prescribe a recognition threshold and measurement process for financial statement recognition and measurement of uncertain tax positions taken or expected to be taken in a tax return, and also provides guidance on the de-recognition of previously recorded benefits and their classification, as well as the proper recording of interest and penalties, accounting in interim periods, disclosures and transition. The Company periodically reviews its income tax positions based on tax laws and regulations and financial reporting considerations, and records adjustments as appropriate. This review takes into consideration the status of current taxing authorities’ examinations of the Company’s tax returns, recent positions taken by the taxing authorities on similar transactions, if any, and the overall tax environment. As of December 31, 2016 , the Company had an insignificant amount of unrecognized tax benefits for uncertain tax positions, none of which if recognized would materially affect the effective tax rate if recognized. The Company does not anticipate that the amount of unrecognized tax benefits will significantly increase or decrease in the next twelve months. The Company’s policy is to recognize interest and penalties on unrecognized tax benefits in income tax expense. The amount of interest and penalties accrued for the years ended December 31, 2016 and 2015 is immaterial. The Company files consolidated income tax returns in Oregon, California, Utah and Idaho and for federal purposes. The Company has tax years 2013–2015 open for tax examination under the statute of limitation provisions of the Internal Revenue Code of 1986 (Code).
Share-Based Compensation	Stock-Based Compensation: The Company has adopted the fair value recognition method for recognizing stock-based compensation expense , using the modified-prospective-transition method. Under that method, compensation costs are recognized based upon grant date fair value. This method requires the cash flows resulting from the tax benefits of tax deductions in excess of the compensation cost recognized for those options (excess tax benefits) to be classified as financing cash flows. The restricted stock grants value shares awarded at their fair value, which is their intrinsic value on the date of the award grant. The expense of the award grants are accrued ratably over the vesting period from the date of each award. Stock Options: Stock option grant stock-based compensation costs under the Company's stock options plans are generally based on the fair value calculated from the Black-Scholes option pricing on the date of the grant award. The Black-Scholes model assumes an expected stock price volatility based on the historical volatility at the date of the grant and an expected term based on the remaining contractual life of the vesting period. The Company bases the estimate of risk-free interest rate on the U.S. Treasury's Constant Maturities Indices in effect at the time of the grant. The dividend yield is based on the current quarterly dividend in effect at the time of the grant. The Company is required to estimate potential forfeitures of stock option grants and adjust compensation cost recorded accordingly. The estimate of forfeitures is adjusted over the requisite service period to the extent that actual forfeitures differ, or are expected to differ, from such estimates. Changes in estimated forfeitures are recognized through a cumulative catch-up adjustment in the period of change and also impact the amount of stock compensation expense to be recognized in future periods.
Earnings Per Share, Policy	Earnings Per Share: Earnings per common share is computed under the two-class method. Pursuant to the two-class method, nonvested stock-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents are participating securities and are included in the computation of EPS. The two-class method is an earnings allocation formula that determines earnings per share for each class of common stock and participating security according to dividends declared (or accumulated) and participation rights in undistributed earnings. Application of the two-class method resulted in the equivalent earnings per share to the treasury method. Basic earnings per common share is computed by dividing net earnings allocated to common shareholders by the weighted-average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect of stock compensation and warrants for common stock using the treasury stock method.
Comprehensive Income	Comprehensive Income: Accounting principles generally require that recognized revenue, expenses, gains and losses be included in net income. In addition, certain changes in assets and liabilities, such as unrealized gains and losses on available-for-sale securities, are reported as a separate component of the equity section of the Consolidated Statements of Financial Condition, and such items, along with net income, are components of comprehensive income (loss) which is reported in the Consolidated Statements of Comprehensive Income.
Business Segments	Business Segments: The Company is managed by legal entity and not by lines of business. Each of the Banks is a community oriented commercial bank chartered in the State of Washington. The Banks’ primary business is that of a traditional banking institution, gathering deposits and originating loans for portfolio in its respective primary market areas. The Banks offer a wide variety of deposit products to their consumer and commercial customers. Lending activities include the origination of real estate, commercial/agriculture business and consumer loans. Banner Bank is also an active participant in the secondary market, originating residential loans for sale on both a servicing released and servicing retained basis. In addition to interest income on loans and investment securities, the Banks receive other income from deposit service charges, loan servicing fees and from the sale of loans and investments. The performance of the Banks is reviewed by the Company’s executive management and Board of Directors on a monthly basis. All of the executive officers of the Company are members of Banner Bank’s management team. Generally Accepted Accounting Principles establish standards to report information about operating segments in annual financial statements and require reporting of selected information about operating segments in interim reports to shareholders. The Company has determined that its current business and operations consist of a single business segment.
Reclassification	Reclassification: Certain reclassifications have been made to the prior years’ consolidated financial statements and/or schedules to conform to the current year’s presentation. These reclassifications may have affected certain reported amounts and ratios for the prior periods. These reclassifications had no effect on retained earnings or net income as previously presented and the effect of these reclassifications is considered immaterial.

BUSINESS COMBINATIONS BUSINES34

BUSINESS COMBINATIONS BUSINESS COMBINATIONS (Tables)	12 Months Ended
	Dec. 31, 2016
Business Acquisition [Line Items]
Schedule of Acquisition Related Costs	The following tables present the key components of acquisition-related costs in connection with the purchase of six Oregon branches in 2014 (the Branch purchase), the acquisition of Siuslaw and the acquisition of Starbuck, including AmericanWest, for the years ended December 31, 2016 , 2015 and 2014 (in thousands): Years Ended December 31 2016 2015 2014 Acquisition-related costs recognized in non-interest expense: Personnel severance/retention fees $ 1,384 $ 6,577 $ — Non-capitalized equipment and repairs 2,590 1,031 105 Client communications 1,158 527 327 Information/computer data services 2,490 2,875 334 Payment and processing expenses 197 28 185 Professional services 2,230 11,169 2,953 Miscellaneous 1,684 3,903 421 $ 11,733 $ 26,110 $ 4,325 The Branch purchase $ — $ — $ 1,784 Siuslaw 95 2,000 748 Starbuck 11,638 24,110 1,793 $ 11,733 $ 26,110 $ 4,325
Siuslaw Financial Group, Inc [Member]
Business Acquisition [Line Items]
Schedule of Components of Business Acquisition	The following table presents a summary of the consideration paid and the estimated fair values as of the acquisition date for each major class of assets acquired and liabilities assumed (in thousands): Siuslaw March 6, 2015 Consideration to Siuslaw shareholders: Cash paid $ 5,806 Fair value of common shares issued 58,100 Total consideration 63,906 Fair value of assets acquired: Cash and cash equivalents $ 84,405 Securities—available-for-sale 12,865 Loans receivable (contractual amount of $252.2 million) 247,098 REO, held for sale 2,525 Property and equipment 8,127 CDI 3,895 Other assets 10,848 Total assets acquired 369,763 Fair value of liabilities assumed: Deposits 316,406 Junior subordinated debentures 5,959 Other liabilities 5,183 Total liabilities assumed 327,548 Net assets acquired $ 42,215 Goodwill 21,691
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period	The following table presents the acquired PCI loans as of the acquisition date (in thousands): Siuslaw March 6, 2015 Acquired PCI loans: Contractually required principal and interest payments $ 11,134 Nonaccretable difference (3,238 ) Cash flows expected to be collected 7,896 Accretable yield (2,239 ) Fair value of PCI loans $ 5,657
Business Acquisition, Pro Forma Information	As a result, actual amounts would have differed from the unaudited pro forma information presented (in thousands except per share amounts): Pro Forma Year Ended December 31 2015 Total revenues (net interest income plus non-interest income) $ 308,153 Net income $ 44,484 Earnings per share - basic $ 1.85 Earnings per share - diluted $ 1.85
Starbuck Bancshares, Inc [Member]
Business Acquisition [Line Items]
Schedule of Components of Business Acquisition	The following table presents a summary of the consideration paid and the estimated fair values as of the acquisition date for each major class of assets acquired and liabilities assumed (in thousands): Starbuck October 1, 2015 Consideration to Starbuck equityholders: Cash paid $ 130,000 Fair value of common shares issued 630,674 Total consideration 760,674 Fair value of assets acquired: Cash and cash equivalents $ 95,821 Securities 1,037,238 Loans receivable (contractual amount of $3.04 billion) 2,999,130 REO, held for sale 6,105 Property and equipment 66,728 CDI 33,500 Deferred tax asset 108,454 Other assets 113,009 Total assets acquired 4,459,985 Fair value of liabilities assumed: Deposits 3,638,596 FHLB advances 221,442 Junior subordinated debentures 5,806 Other liabilities 56,359 Total liabilities assumed 3,922,203 Net assets acquired 537,782 Goodwill $ 222,892
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period	The following table presents the acquired PCI loans as of the acquisition date (in thousands): Starbuck October 1, 2015 Acquired PCI loans: Contractually required principal and interest payments $ 98,746 Nonaccretable difference (26,162 ) Cash flows expected to be collected 72,584 Accretable yield (11,071 ) Fair value of PCI loans $ 61,513
Business Acquisition, Pro Forma Information	As a result, actual amounts would have differed from the unaudited pro forma information presented (in thousands except per share amounts): Pro Forma Year Ended December 31 2015 Total revenues (net interest income plus non-interest income) $ 455,427 Net income $ 86,255 Earnings per share - basic $ 2.56 Earnings per share - diluted $ 2.55

SECURITIES (Tables)

SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Schedule of Securities	The amortized cost, gross unrealized losses and gains and estimated fair value of securities at December 31, 2016 and 2015 are summarized as follows (in thousands): December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Trading: U.S. Government and agency obligations $ 1,230 $ 1,326 Municipal bonds 331 335 Corporate bonds 26,959 21,143 Mortgage-backed or related securities 1,620 1,641 Equity securities 14 123 $ 30,154 $ 24,568 Available-for-Sale: U.S. Government and agency obligations $ 57,288 $ 146 $ (456 ) $ 56,978 Municipal bonds 110,487 455 (1,089 ) 109,853 Corporate bonds 10,255 77 (49 ) 10,283 Mortgage-backed or related securities 598,899 2,064 (6,251 ) 594,712 Asset-backed securities 29,319 — (326 ) 28,993 Equity securities 88 10 — 98 $ 806,336 $ 2,752 $ (8,171 ) $ 800,917 Held-to-Maturity: U.S. Government and agency obligations $ 1,065 $ — $ (18 ) $ 1,047 Municipal bonds: 196,989 4,173 (1,272 ) 199,890 Corporate bonds 3,876 — — 3,876 Mortgage-backed or related securities 65,943 309 (537 ) 65,715 $ 267,873 $ 4,482 $ (1,827 ) $ 270,528 December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Trading: U.S. Government and agency obligations $ 1,230 $ 1,368 Municipal bonds 332 341 Corporate bonds 25,063 18,699 Mortgage-backed or related securities 12,705 13,663 Equity securities 14 63 $ 39,344 $ 34,134 Available-for-Sale: U.S. Government and agency obligations $ 30,211 $ 213 $ (193 ) $ 30,231 Municipal bonds 142,898 853 (432 ) 143,319 Corporate bonds 15,937 56 (12 ) 15,981 Mortgage-backed or related securities 919,318 4,056 (5,115 ) 918,259 Asset-backed securities 31,288 — (603 ) 30,685 Equity securities 88 10 — 98 $ 1,139,740 $ 5,188 $ (6,355 ) $ 1,138,573 Held-to-Maturity: U.S. Government and agency obligations $ 1,106 $ 5 $ — $ 1,111 Municipal bonds: 162,778 6,219 (191 ) 168,806 Corporate bonds 4,273 — — 4,273 Mortgage-backed or related securities 52,509 253 (325 ) 52,437 $ 220,666 $ 6,477 $ (516 ) $ 226,627
Schedule of Securities with Continuous Loss Position	At December 31, 2016 and 2015 , the gross unrealized losses and the fair value for securities available-for-sale and held-to-maturity aggregated by the length of time that individual securities have been in a continuous unrealized loss position was as follows (in thousands): December 31, 2016 Less Than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Available-for-Sale: U.S. Government and agency obligations $ 39,043 $ (442 ) $ 1,012 $ (14 ) $ 40,055 $ (456 ) Municipal bonds 60,765 (1,087 ) 556 (2 ) 61,321 (1,089 ) Corporate bonds 5,206 (49 ) — — 5,206 (49 ) Mortgage-backed or related securities 403,431 (5,604 ) 47,467 (647 ) 450,898 (6,251 ) Asset-backed securities 9,928 (101 ) 19,064 (225 ) 28,992 (326 ) $ 518,373 $ (7,283 ) $ 68,099 $ (888 ) $ 586,472 $ (8,171 ) Held-to-Maturity: U.S. Government and agency obligations $ 1,047 $ (18 ) $ — $ — $ 1,047 $ (18 ) Municipal bonds $ 64,802 $ (1,267 ) $ 204 $ (5 ) $ 65,006 $ (1,272 ) Mortgage-backed or related securities 42,245 (537 ) — — 42,245 (537 ) $ 108,094 $ (1,822 ) $ 204 $ (5 ) $ 108,298 $ (1,827 ) December 31, 2015 Less Than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Available-for-Sale: U.S. Government and agency obligations $ 8,707 $ (97 ) $ 10,489 $ (96 ) $ 19,196 $ (193 ) Municipal bonds 69,848 (426 ) 905 (6 ) 70,753 (432 ) Corporate bonds 5,153 (12 ) — — 5,153 (12 ) Mortgage-backed or related securities 533,143 (4,380 ) 68,562 (735 ) 601,705 (5,115 ) Asset-backed securities 20,893 (355 ) 9,792 (248 ) 30,685 (603 ) $ 637,744 $ (5,270 ) $ 89,748 $ (1,085 ) $ 727,492 $ (6,355 ) Held-to-Maturity: Municipal bonds $ 28,545 $ (188 ) $ 254 $ (3 ) $ 28,799 $ (191 ) Mortgage-backed or related securities 34,493 (323 ) 255 (2 ) 34,748 (325 ) $ 63,038 $ (511 ) $ 509 $ (5 ) $ 63,547 $ (516 )
Schedule of Securities by Contractual Maturity Date	The amortized cost and estimated fair value of securities at December 31, 2016 , by contractual maturity, are shown below (in thousands). Expected maturities will differ from contractual maturities because some securities may be called or prepaid with or without call or prepayment penalties. December 31, 2016 Trading Available-for-Sale Held-to-Maturity Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Maturing in one year or less $ 1,751 $ 1,775 $ 13,077 $ 13,063 $ 1,962 $ 1,975 Maturing after one year through five years 230 231 120,405 120,126 18,988 19,000 Maturing after five years through ten years 1,200 1,296 176,010 173,720 113,587 114,336 Maturing after ten years through twenty years — — 188,557 187,940 88,546 91,098 Maturing after twenty years 26,959 21,143 308,199 305,970 44,790 44,119 30,140 24,445 806,248 800,819 267,873 270,528 Equity securities 14 123 88 98 — — $ 30,154 $ 24,568 $ 806,336 $ 800,917 $ 267,873 $ 270,528
Schedule of Pledged Securities	The following table presents, as of December 31, 2016 , investment securities which were pledged to secure borrowings, public deposits or other obligations as permitted or required by law (in thousands): Carrying Value Amortized Cost Fair Value Purpose or beneficiary: State and local governments public deposits $ 203,510 $ 203,474 $ 207,013 Interest rate swap counterparties 24,393 24,447 24,287 Repurchase transaction accounts 114,949 115,650 114,864 Other 1,778 1,782 1,778 Total pledged securities $ 344,630 $ 345,353 $ 347,942

LOANS RECEIVABLE AND THE ALLO36

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Tables)	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Impaired loans excluding purchased credit impaired loans [Table Text Block]	The following tables provide additional information on impaired loans, excluding PCI loans, with and without specific allowance reserves at December 31, 2016 and 2015 . Recorded investment includes the unpaid principal balance or the carrying amount of loans less charge-offs and net deferred loan fees (in thousands): December 31, 2016 Unpaid Principal Balance Recorded Investment Related Allowance Without Allowance (1) With Allowance (2) Commercial real estate: Owner-occupied $ 3,786 $ 1,778 $ 1,798 $ 175 Investment properties 9,916 4,015 5,854 580 Multifamily real estate 508 — 496 81 One- to four-family construction 1,180 — 1,180 156 Land and land development: Residential 3,012 750 1,106 219 Commercial 1,608 998 — — Commercial business 3,753 2,294 1,431 154 Agricultural business/farmland 6,438 5,886 468 35 One- to four-family residential 11,439 90 11,085 655 Consumer: Consumer secured by one- to four-family 1,904 — 1,865 179 Consumer—other 391 4 388 29 $ 43,935 $ 15,815 $ 25,671 $ 2,263 December 31, 2015 Unpaid Principal Balance Recorded Investment Related Allowance Without Allowance (1) With Allowance (2) Commercial real estate: Owner-occupied $ 1,465 $ — $ 1,416 $ 70 Investment properties 8,740 2,503 5,846 602 Multifamily real estate 359 — 357 71 Commercial construction 1,141 1,069 — — One- to four-family construction 1,741 — 1,741 161 Land and land development: Residential 3,540 750 1,634 444 Commercial 1,628 1,027 — — Commercial business 2,266 538 1,184 150 Agricultural business/farmland 1,309 544 697 43 One- to four-family residential 17,897 2,206 14,418 736 Consumer: Consumer secured by one- to four-family 776 — 716 23 Consumer—other 433 — 351 7 $ 41,295 $ 8,637 $ 28,360 $ 2,307 (1) Loans without an allowance reserve have been individually evaluated for impairment and that evaluation concluded that no reserve was needed. (2) Includes general reserves for loans evaluated in pools of homogeneous loans and loans with a specific reserve allowance. Loans with a specific allowance reserve have been individually evaluated for impairment using either a discounted cash flow analysis or, for collateral dependent loans, current appraisals less costs to sell to establish realizable value.
Allowance for Credit Losses on Financing Receivables [Table Text Block]	The following tables provide additional information on the allowance for loan losses and loan balances individually and collectively evaluated for impairment at or for the year ended December 31, 2016 (in thousands): For the Year Ended December 31, 2016 Commercial Real Estate Multifamily Real Estate Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance for loan losses: Beginning balance $ 20,716 $ 4,195 $ 27,131 $ 13,856 $ 3,645 $ 4,732 $ 902 $ 2,831 $ 78,008 Provision for loan losses 441 (2,835 ) 5,566 1,632 (170 ) (3,402 ) 4,079 719 6,030 Recoveries 582 — 2,171 1,993 59 1,283 610 — 6,698 Charge-offs (746 ) — (616 ) (948 ) (567 ) (375 ) (1,487 ) — (4,739 ) Ending balance $ 20,993 $ 1,360 $ 34,252 $ 16,533 $ 2,967 $ 2,238 $ 4,104 $ 3,550 $ 85,997 December 31, 2016 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance individually evaluated for impairment $ 428 $ 64 $ 374 $ 69 $ — $ 480 $ 5 $ — $ 1,420 Allowance collectively evaluated for impairment 20,565 1,296 33,845 16,464 2,967 1,758 4,099 3,550 84,544 Allowance for purchased credit-impaired loans — — 33 — — — — — 33 Total allowance for loan losses $ 20,993 $ 1,360 $ 34,252 $ 16,533 $ 2,967 $ 2,238 $ 4,104 $ 3,550 $ 85,997 December 31, 2016 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Loan balances: Loans individually evaluated for impairment $ 10,300 $ 349 $ 4,034 $ 2,946 $ 4,766 $ 7,678 $ 309 $ — $ 30,382 Loans collectively evaluated for impairment 3,305,586 247,662 815,174 1,201,112 363,706 805,125 650,079 — 7,388,444 Purchased credit-impaired loans 23,449 139 3,878 3,821 684 274 77 — 32,322 Total loans $ 3,339,335 $ 248,150 $ 823,086 $ 1,207,879 $ 369,156 $ 813,077 $ 650,465 $ — $ 7,451,148 The following tables provide additional information on the allowance for loan losses and loan balances individually and collectively evaluated for impairment at or for the year ended December 31, 2015 (in thousands): For the Year Ended December 31, 2015 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance for loan losses: Beginning balance $ 18,784 $ 4,562 $ 25,545 $ 12,043 $ 3,821 $ 5,447 $ 483 $ 5,222 $ 75,907 Provision for loan losses 1,177 (480 ) 666 1,611 (878 ) (1,068 ) 1,363 (2,391 ) — Recoveries 819 113 1,811 948 1,927 772 570 — 6,960 Charge-offs (64 ) — (891 ) (746 ) (1,225 ) (419 ) (1,514 ) — (4,859 ) Ending balance $ 20,716 $ 4,195 $ 27,131 $ 13,856 $ 3,645 $ 4,732 $ 902 $ 2,831 $ 78,008 December 31, 2015 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance individually evaluated for impairment $ 605 $ 71 $ 418 $ 69 $ — $ 728 $ 29 $ — $ 1,920 Allowance collectively evaluated for impairment 20,111 4,124 26,713 13,732 3,645 4,004 873 2,831 76,033 Allowance for purchased credit-impaired loans — — — 55 — — — — 55 Total allowance for loan losses $ 20,716 $ 4,195 $ 27,131 $ 13,856 $ 3,645 $ 4,732 $ 902 $ 2,831 $ 78,008 December 31, 2015 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Loan balances: Loans individually evaluated for impairment $ 8,519 $ 357 $ 4,669 $ 2,223 $ 544 $ 12,185 $ 319 $ — $ 28,816 Loans collectively evaluated for impairment 3,043,656 470,625 564,051 1,198,419 374,458 939,382 636,497 — 7,227,088 Purchased credit-impaired loans 40,985 1,994 5,650 7,302 1,529 1,066 74 — 58,600 Total loans $ 3,093,160 $ 472,976 $ 574,370 $ 1,207,944 $ 376,531 $ 952,633 $ 636,890 $ — $ 7,314,504
Past Due Financing Receivables [Table Text Block]	The following tables provide additional detail on the age analysis of Banner’s past due loans as of December 31, 2016 and 2015 (in thousands): December 31, 2016 30 – 59 Days Past Due 60 – 89 Days Past Due 90 Days or More Past Due Total Past Due Purchased Credit-Impaired Current Total Loans Loans 90 Days or More Past Due and Accruing Non-accrual Commercial real estate: Owner-occupied $ 1,938 $ — $ 2,538 $ 4,476 $ 13,281 $ 1,335,242 $ 1,352,999 $ — $ 3,373 Investment properties 117 — 5,447 5,564 10,168 1,970,604 1,986,336 701 4,864 Multifamily real estate — — 147 147 139 247,864 248,150 147 — Commercial construction — — — — — 124,068 124,068 — — Multifamily construction — — — — — 124,126 124,126 — — One- to four-family construction — — — — 862 374,842 375,704 — — Land and land development: Residential 48 — 750 798 — 169,206 170,004 — 750 Commercial — — 998 998 3,016 25,170 29,184 — 998 Commercial business 2,314 647 1,591 4,552 3,821 1,199,506 1,207,879 — 3,074 Agricultural business/farmland 360 1,244 2,768 4,372 684 364,100 369,156 — 3,229 One- to four-family residential 1,793 249 2,110 4,152 274 808,651 813,077 1,233 2,263 Consumer: Consumer secured by one- to four-family 932 160 986 2,078 18 491,115 493,211 61 1,660 Consumer—other 1,421 154 147 1,722 59 155,473 157,254 11 215 Total $ 8,923 $ 2,454 $ 17,482 $ 28,859 $ 32,322 $ 7,389,967 $ 7,451,148 $ 2,153 $ 20,426 December 31, 2015 30–59 Days Past Due 60–89 Days Past Due 90 Days or More Past Due Total Past Due Purchased Credit-Impaired Current Total Loans Loans 90 Days or More Past Due and Accruing Non-accrual Commercial real estate: Owner-occupied $ 3,981 $ 139 $ 885 $ 5,005 $ 24,261 $ 1,298,541 $ 1,327,807 $ — $ 1,235 Investment properties 1,763 132 2,503 4,398 16,724 1,744,231 1,765,353 — 2,516 Multifamily real estate 4 — — 4 1,994 470,978 472,976 — — Commercial construction — — — — — 72,103 72,103 — — Multifamily construction 771 13 — 784 — 63,062 63,846 — — One- to four-family construction 2,466 220 — 2,686 905 274,878 278,469 — 1,233 Land and land development: Residential — — 747 747 77 125,949 126,773 — 1,027 Commercial — 96 — 96 4,668 28,415 33,179 — — Commercial business 1,844 174 1,024 3,042 7,302 1,197,600 1,207,944 8 2,159 Agricultural business/farmland 323 729 278 1,330 1,529 373,672 376,531 — 697 One- to four-family residential 620 873 3,811 5,304 1,066 946,263 952,633 899 4,700 Consumer: Consumer secured by one- to four-family 465 60 38 563 40 477,817 478,420 4 565 Consumer—other 488 155 131 774 34 157,662 158,470 41 138 Total $ 12,725 $ 2,591 $ 9,417 $ 24,733 $ 58,600 $ 7,231,171 $ 7,314,504 $ 952 $ 14,270
Schedule of Loans Receivable, Including Loans Held for Sale	Loans receivable at December 31, 2016 and 2015 are summarized as follows (dollars in thousands): December 31, 2016 December 31, 2015 Amount Percent of Total Amount Percent of Total Commercial real estate: Owner-occupied $ 1,352,999 18.1 % $ 1,327,807 18.2 % Investment properties 1,986,336 26.7 1,765,353 24.1 Multifamily real estate 248,150 3.3 472,976 6.5 Commercial construction 124,068 1.7 72,103 1.0 Multifamily construction 124,126 1.7 63,846 0.9 One- to four-family construction 375,704 5.0 278,469 3.8 Land and land development: Residential 170,004 2.3 126,773 1.7 Commercial 29,184 0.4 33,179 0.5 Commercial business 1,207,879 16.2 1,207,944 16.5 Agricultural business, including secured by farmland 369,156 5.0 376,531 5.1 One- to four-family residential 813,077 10.9 952,633 13.0 Consumer: Consumer secured by one- to four-family 493,211 6.6 478,420 6.5 Consumer—other 157,254 2.1 158,470 2.2 Total loans outstanding 7,451,148 100.0 % 7,314,504 100.0 % Less allowance for loan losses (85,997 ) (78,008 ) Net loans $ 7,365,151 $ 7,236,496 Loan amounts are net of unearned loan fees in excess of unamortized costs of $5.8 million at December 31, 2016 and $5.5 million at December 31, 2015 . Net loans include net discounts on acquired loans of $31.1 million and $43.7 million as of December 31, 2016 and 2015 , respectively.
Schedule of Purchased Credit-Impaired Loans, Changes in Accretable Yield	The following table presents the changes in the accretable yield for PCI loans for the years ended December 31, 2016 and 2015 (in thousands): Years Ended December 31 2016 2015 Balance, beginning of period $ 10,375 $ — Additions — 13,310 Accretion to interest income (9,333 ) (2,202 ) Disposals and other (1,018 ) (1,238 ) Reclassifications from non-accretable difference 8,693 505 Balance, end of period $ 8,717 $ 10,375
Schedule of Impaired Loans With and Without Specific Reserves	The following tables provide additional information on impaired loans, excluding PCI loans, with and without specific allowance reserves at December 31, 2016 and 2015 . Recorded investment includes the unpaid principal balance or the carrying amount of loans less charge-offs and net deferred loan fees (in thousands): December 31, 2016 Unpaid Principal Balance Recorded Investment Related Allowance Without Allowance (1) With Allowance (2) Commercial real estate: Owner-occupied $ 3,786 $ 1,778 $ 1,798 $ 175 Investment properties 9,916 4,015 5,854 580 Multifamily real estate 508 — 496 81 One- to four-family construction 1,180 — 1,180 156 Land and land development: Residential 3,012 750 1,106 219 Commercial 1,608 998 — — Commercial business 3,753 2,294 1,431 154 Agricultural business/farmland 6,438 5,886 468 35 One- to four-family residential 11,439 90 11,085 655 Consumer: Consumer secured by one- to four-family 1,904 — 1,865 179 Consumer—other 391 4 388 29 $ 43,935 $ 15,815 $ 25,671 $ 2,263 December 31, 2015 Unpaid Principal Balance Recorded Investment Related Allowance Without Allowance (1) With Allowance (2) Commercial real estate: Owner-occupied $ 1,465 $ — $ 1,416 $ 70 Investment properties 8,740 2,503 5,846 602 Multifamily real estate 359 — 357 71 Commercial construction 1,141 1,069 — — One- to four-family construction 1,741 — 1,741 161 Land and land development: Residential 3,540 750 1,634 444 Commercial 1,628 1,027 — — Commercial business 2,266 538 1,184 150 Agricultural business/farmland 1,309 544 697 43 One- to four-family residential 17,897 2,206 14,418 736 Consumer: Consumer secured by one- to four-family 776 — 716 23 Consumer—other 433 — 351 7 $ 41,295 $ 8,637 $ 28,360 $ 2,307 (1) Loans without an allowance reserve have been individually evaluated for impairment and that evaluation concluded that no reserve was needed. (2) Includes general reserves for loans evaluated in pools of homogeneous loans and loans with a specific reserve allowance. Loans with a specific allowance reserve have been individually evaluated for impairment using either a discounted cash flow analysis or, for collateral dependent loans, current appraisals less costs to sell to establish realizable value. The following table summarizes our average recorded investment and interest income recognized on impaired loans by loan class for the years ended December 31, 2016 , 2015 and 2014 (in thousands): Year Ended December 31, 2016 Year Ended December 31, 2015 Year Ended December 31, 2014 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial real estate: Owner-occupied $ 2,721 $ 2 $ 1,467 $ 9 $ 1,841 $ 12 Investment properties 18,529 242 8,003 303 6,145 315 Multifamily real estate 513 21 362 18 795 45 One- to four-family construction 1,158 75 1,463 114 2,655 118 Land and land development: Residential 1,948 85 2,406 49 2,872 89 Commercial 1,003 — 931 — — — Commercial business 4,290 37 1,667 35 1,328 41 Agricultural business/farmland 5,004 119 1,143 19 1,866 — One- to four-family residential 11,976 441 17,770 630 26,093 870 Consumer: Consumer secured by one- to four-family 1,778 17 736 11 1,248 19 Consumer—other 615 17 392 18 597 19 $ 49,535 $ 1,056 $ 36,340 $ 1,206 $ 45,440 $ 1,528
Schedule of Troubled Debt Restructurings	The following table presents TDRs by accrual and nonaccrual status at December 31, 2016 and 2015 (in thousands): December 31, 2016 December 31, 2015 Accrual Status Nonaccrual Status Total TDRs Accrual Nonaccrual Total Commercial real estate: Owner-occupied $ 203 $ 96 $ 299 $ 181 $ 104 $ 285 Investment properties 4,304 — 4,304 5,834 13 5,847 Multifamily real estate 349 — 349 357 — 357 One- to four-family construction 1,180 — 1,180 1,741 — 1,741 Land and land development: Residential 1,106 — 1,106 1,151 483 1,634 Commercial business 653 — 653 624 — 624 Agricultural business/farmland 3,125 79 3,204 545 277 822 One- to four-family residential 7,678 843 8,521 11,025 1,428 12,453 Consumer: Consumer secured by one- to four-family 143 6 149 147 14 161 Consumer—other 166 — 166 172 — 172 $ 18,907 $ 1,024 $ 19,931 $ 21,777 $ 2,319 $ 24,096 As of December 31, 2016 and 2015 , the Company had commitments to advance funds up to an additional amount of $127,000 and $237,000 , respectively, related to TDRs.
Schedule of Newly Restructured Loans	The following table presents new TDRs that occurred during the years ended December 31, 2016 and 2015 (dollars in thousands): Year Ended December 31, 2016 Year Ended December 31, 2015 Number of Contracts Pre-modification Outstanding Recorded Investment Post-modification Outstanding Recorded Investment Number of Pre-modification Outstanding Recorded Investment Post-modification Outstanding Recorded Investment Recorded Investment (1) (2) Commercial real estate: Owner-occupied 1 $ 194 $ 194 — $ — $ — Land and land development: Residential — — — 2 1,302 483 Agricultural business/farmland — — — 3 822 822 One- to four-family residential 1 78 78 2 431 431 2 $ 272 $ 272 7 $ 2,555 $ 1,736 (1) Since most loans were already considered classified and/or on non-accrual status prior to restructuring, the modifications did not have a material effect on the Company’s determination of the allowance for loan losses. (2) The majority of these modifications do not fit into one separate type, such as rate, term, amount, interest-only or payment, but instead are a combination of multiple types of modifications; therefore, they are disclosed in aggregate.
Schedule of Troubled Debt Restructurings Which Incurred A Payment Default	The following table presents TDRs which incurred a payment default within the year ended December 31, 2015 for which the payment default occurred within twelve months of the restructure date. There were no TDRs that incurred a payment default in the year ended December 31, 2016. A default on a restructured loan results in a transfer to nonaccrual status, a charge-off or a combination of both (dollars in thousands): December 31, 2015 Number of Loans Amount Agricultural business/farmland 2 $ 277 One- to four-family residential 1 387 Total 3 $ 664
Financing Receivable Credit Quality Indicators [Table Text Block]	The following tables show Banner’s portfolio of risk-rated loans and non-risk-rated loans by grade or other characteristic as of December 31, 2016 and 2015 (in thousands): December 31, 2016 By class: Pass (Risk Ratings 1-5) (1) Special Substandard Doubtful Loss Total Loans Commercial real estate: Owner-occupied $ 1,313,142 $ 14,394 $ 25,463 $ — $ — $ 1,352,999 Investment properties 1,948,822 23,846 13,668 — — 1,986,336 Multifamily real estate 247,258 — 892 — — 248,150 Commercial construction 124,068 — — — — 124,068 Multifamily construction 124,126 — — — — 124,126 One- to four-family construction 371,636 — 4,068 — — 375,704 Land and land development: Residential 167,764 — 2,240 — — 170,004 Commercial 25,090 — 4,094 — — 29,184 Commercial business 1,148,585 35,036 24,258 — — 1,207,879 Agricultural business, including secured by farmland 356,656 3,335 9,165 — — 369,156 One- to four-family residential 807,837 967 4,273 — — 813,077 Consumer: Consumer secured by one- to four-family 490,877 5 2,327 2 — 493,211 Consumer—other 156,547 108 594 5 — 157,254 Total $ 7,282,408 $ 77,691 $ 91,042 $ 7 $ — $ 7,451,148 December 31, 2015 By class: Pass (Risk Ratings 1-5) (1) Special Substandard Doubtful Loss Total Loans Commercial real estate: Owner-occupied $ 1,281,561 $ 19,400 $ 26,846 $ — $ — $ 1,327,807 Investment properties 1,740,720 11,528 13,105 — — 1,765,353 Multifamily real estate 468,467 138 4,371 — — 472,976 Commercial construction 72,103 — — — — 72,103 Multifamily construction 63,846 — — — — 63,846 One- to four-family construction 275,154 — 3,315 — — 278,469 Land and land development: Residential 121,536 76 5,161 — — 126,773 Commercial 25,786 2,310 5,083 — — 33,179 Commercial business 1,167,933 25,286 14,725 — — 1,207,944 Agricultural business, including secured by farmland 354,760 17,526 4,245 — — 376,531 One- to four-family residential 943,098 1,346 8,189 — — 952,633 Consumer: Consumer secured by one- to four-family 476,448 — 1,967 5 — 478,420 Consumer—other 157,286 22 1,157 5 — 158,470 Total $ 7,148,698 $ 77,632 $ 88,164 $ 10 $ — $ 7,314,504 (1) The Pass category includes some performing loans that are part of homogenous pools which are not individually risk-rated. This includes all consumer loans, all one- to four-family residential loans and, as of December 31, 2016 and 2015 , in the commercial business category, $225.0 million and $150.0 million , respectively, of credit-scored small business loans. As loans in these homogeneous pools become non-accrual, they are individually risk-rated. (2) Non-performing loans include non-accrual loans and loans past due greater than 90 days but still on accrual status.

REAL ESTATE OWNED, HELD FOR S37

REAL ESTATE OWNED, HELD FOR SALE, NET (Tables)	12 Months Ended
	Dec. 31, 2016
Real Estate [Abstract]
Schedule of Changes in Real Estate Owned, Net of Valuation Allowance	The following table presents the changes in REO, net of valuation allowance, for the years ended December 31, 2016 , 2015 and 2014 (in thousands): Years Ended December 31 2016 2015 2014 Balance, beginning of period $ 11,627 $ 3,352 $ 4,044 Additions from loan foreclosures 8,909 4,351 3,264 Additions from capitalized costs — 298 30 Additions from acquisitions 400 8,231 — Proceeds from dispositions of REO (10,812 ) (4,740 ) (4,923 ) Gain on sale of REO 1,833 351 973 Valuation adjustments in the period (876 ) (216 ) (36 ) Balance, end of period $ 11,081 $ 11,627 $ 3,352

PROPERTY AND EQUIPMENT, NET (Ta

PROPERTY AND EQUIPMENT, NET (Tables)	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Land, buildings and equipment owned by the Company and its subsidiaries at December 31, 2016 and 2015 are summarized as follows (in thousands): December 31 2016 2015 Land (1) $ 35,463 $ 38,992 Buildings and leasehold improvements (1) 162,342 160,075 Furniture and equipment 91,706 79,018 289,511 278,085 Less accumulated depreciation (123,030 ) (110,481 ) Property and equipment, net $ 166,481 $ 167,604
Schedule of Future Minimum Rental Payments for Operating Leases	The Company’s obligations under long-term property leases are as follows: Year Amount 2017 $ 14.6 million 2018 12.7 million 2019 10.1 million 2020 8.8 million 2021 7.2 million Thereafter 16.1 million Total $ 69.5 million

DEPOSITS (Tables)

DEPOSITS (Tables)	12 Months Ended
	Dec. 31, 2016
Banking and Thrift [Abstract]
Schedule of Deposit Liabilities	Deposits consist of the following at December 31, 2016 and 2015 (in thousands): December 31 2016 2015 Non-interest-bearing checking $ 3,140,451 $ 2,619,618 Interest-bearing checking 914,484 1,159,846 Regular savings accounts 1,523,391 1,284,642 Money market accounts 1,497,755 1,637,092 Total interest-bearing transaction and savings accounts 3,935,630 4,081,580 Certificates of deposit: Certificates of deposit less than or equal to $250,000 884,403 1,168,495 Certificates of deposit greater than $250,000 160,930 185,375 Total certificates of deposit (1) 1,045,333 1,353,870 Total deposits $ 8,121,414 $ 8,055,068 Included in total deposits: Public fund transaction accounts $ 221,765 $ 209,430 Public fund interest-bearing certificates 25,650 31,281 Total public deposits $ 247,415 $ 240,711 Total brokered deposits $ 34,074 $ 162,936 (1) Certificates of deposit includes $426,000 and $2.0 million of acquisition premiums at December 31, 2016 and 2015 , respectively. Deposits at December 31, 2016 and 2015 included deposits from the Company’s directors, executive officers and related entities totaling $7.2 million and $6.6 million , respectively.
Schedule Maturities and Weighted Average Interest Rates of Certificates of Deposit	Scheduled maturities and weighted average interest rates of certificate accounts at December 31, 2016 are as follows (dollars in thousands): December 31, 2016 Amount Weighted Average Rate Maturing in one year or less $ 765,406 0.45 % Maturing after one year through two years 159,436 0.76 Maturing after two years through three years 60,932 0.88 Maturing after three years through four years 26,238 1.19 Maturing after four years through five years 29,912 1.06 Maturing after five years 3,409 1.26 Total certificates of deposit $ 1,045,333 0.56 %

ADVANCES FROM FEDERAL HOME LO40

ADVANCES FROM FEDERAL HOME LOAN BANK OF DES MOINES (Tables)	12 Months Ended
	Dec. 31, 2016
Advances from Federal Home Loan Banks [Abstract]
Schedule of Federal Home Loan Bank Advances, Fiscal Year Maturity	At December 31, 2016 and 2015 , FHLB advances were scheduled to mature as follows (in thousands): December 31 2016 2015 Maturing in one year or less $ 54,000 $ 107,600 Maturing after one year through three years — 25,000 Maturing after three years through five years — — Maturing after five years 179 188 Total FHLB advances, at par 54,179 132,788 Fair value adjustment 37 593 Total FHLB advances, carried at fair value $ 54,216 $ 133,381

OTHER BORROWINGS (Tables)

OTHER BORROWINGS (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule of Other Borrowings, Maturity	A summary of all other borrowings at December 31, 2016 and 2015 by the period remaining to maturity is as follows (dollars in thousands): At or for the Years Ended December 31 2016 2015 Amount Weighted Average Rate Amount Weighted Average Rate Repurchase agreements: Maturing in one year or less $ 100,685 0.19 % $ 93,325 0.19 % Maturing after one year through two years 5,000 2.15 — — Maturing after two years — — 5,000 2.15 Total year-end outstanding $ 105,685 0.28 $ 98,325 0.29 Average outstanding $ 108,427 0.29 $ 94,182 0.22 Maximum outstanding at any month-end 112,309 n/a 102,474 n/a

JUNIOR SUBORDINATED DEBENTURE42

JUNIOR SUBORDINATED DEBENTURES AND MANDATORILY REDEEMABLE TRUST PREFERRED SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Schedule of Trust Preferred Securities	The following table is a summary of trust preferred securities at December 31, 2016 (dollars in thousands): Name of Trust Aggregate Liquidation Amount of Trust Preferred Securities Aggregate Liquidation Amount of Common Capital Securities Aggregate Principal Amount of Junior Subordinated Debentures Stated Maturity (1) Current Interest Rate Reset Period Interest Rate Spread Banner Capital Trust II $ 15,000 $ 464 $ 15,464 2033 4.23 % Quarterly Three-month LIBOR + 3.35% Banner Capital Trust III 15,000 465 15,465 2033 3.78 Quarterly Three-month LIBOR + 2.90% Banner Capital Trust IV 15,000 465 15,465 2034 3.73 Quarterly Three-month LIBOR + 2.85% Banner Capital Trust V 25,000 774 25,774 2035 2.49 Quarterly Three-month LIBOR + 1.57% Banner Capital Trust VI 25,000 774 25,774 2037 2.46 Quarterly Three-month LIBOR + 1.62% Banner Capital Trust VII 25,000 774 25,774 2037 2.23 Quarterly Three-month LIBOR + 1.38% Siuslaw Statutory Trust I 8,000 248 8,248 2034 3.69 Quarterly Three-month LIBOR + 2.70% Greater Sacramento Bancorp Statutory Trust I 4,000 124 4,124 2033 4.23 Quarterly Three-month LIBOR + 3.35% Greater Sacramento Bancorp Statutory Trust II 4,000 124 4,124 2035 2.64 Quarterly Three-month LIBOR + 1.68% Total TPS liability at par $ 136,000 $ 4,212 140,212 3.03 % Fair value adjustment (45,012 ) Total TPS liability at fair value $ 95,200 (1) All of the Company's trust preferred securities are eligible for redemption.

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The following table presents the components of the provision for income taxes included in the Consolidated Statements of Operations for the years ended December 31, 2016 , 2015 and 2014 (in thousands): Years Ended December 31 2016 2015 2014 Current Federal $ 29,787 $ 24,683 $ 23,411 State 2,477 1,399 1,444 Total Current 32,264 26,082 24,855 Deferred Federal 9,908 (3,310 ) 2,764 State 2,083 (23 ) (567 ) Total Deferred 11,991 (3,333 ) 2,197 Provision for income taxes $ 44,255 $ 22,749 $ 27,052
Schedule of Effective Income Tax Rate Reconciliation	The following table presents the reconciliation of the federal statutory rate to the actual effective rate for the years ended December 31, 2016 , 2015 and 2014 : Years Ended December 31 2016 2015 2014 Federal income tax statutory rate 35.0 % 35.0 % 35.0 % Increase (decrease) in tax rate due to: Tax-exempt interest (2.6 ) (3.9 ) (2.6 ) Investment in life insurance (1.2 ) (1.3 ) (0.8 ) State income taxes, net of federal tax offset 2.2 1.1 1.1 Tax credits (0.8 ) (1.6 ) (0.8 ) Merger and acquisition costs — 1.9 0.7 Other 1.5 2.3 0.7 Effective income tax rate 34.1 % 33.5 % 33.3 %
Schedule of Net Deferred Tax Asset	The following table reflects the effect of temporary differences that gave rise to the components of the net deferred tax asset as of December 31, 2016 and 2015 (in thousands): December 31 2016 2015 Deferred tax assets: Loan loss and REO $ 36,719 $ 33,312 Deferred compensation 23,189 19,253 Net operating loss carryforward 82,714 91,893 Federal and state tax credits 7,711 7,877 State net operating losses 7,396 8,692 Loan discount 9,696 13,412 Other 6,217 5,620 Total deferred tax assets 173,642 180,059 Deferred tax liabilities: Depreciation (2,218 ) (1,103 ) Deferred loan fees, servicing rights and loan origination costs (13,291 ) (9,884 ) Intangibles (11,178 ) (13,320 ) Financial instruments accounted for under fair value accounting (16,186 ) (17,112 ) Unrealized (gain) loss on securities - available-for-sale (880 ) (1,475 ) Total deferred tax liabilities (43,753 ) (42,894 ) Deferred income tax asset 129,889 137,165 Valuation allowance (2,195 ) (2,195 ) Deferred tax asset, net $ 127,694 $ 134,970
Schedule of Affordable Housing Tax Credit Information	The following table presents the balances of the Company's tax credit investments and related unfunded commitments at December 31, 2016 and 2015 (in thousands): December 31, 2016 December 31, 2015 Tax credit investments $ 4,654 $ 5,326 Unfunded commitments—tax credit investments 665 1,398 The following table presents other information related to the Company's tax credit investments for the years ended December 31, 2016 and 2015 (in thousands): For the year ended December 31, 2016 2015 Tax credits and other tax benefits recognized $ 1,136 $ 1,273 Tax credit amortization expense included in provision for income taxes 672 1,000

STOCK-BASED COMPENSATION PLANS

STOCK-BASED COMPENSATION PLANS (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Financial Data Pertaining to Outstanding Stock Options, by Exercise Price Range	At December 31, 2016 , financial data pertaining to outstanding stock options was as follows: Exercise Price Weighted Average Exercise Price of Option Shares Granted Number of Option Shares Granted Weighted Average Option Shares Vested and Exercisable Weighted Average Exercise Price of Option Shares Exercisable Remaining Contractual Life $ 216.16 $ 216.16 5,000 5,000 $ 216.16 7 months
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	A summary of the Company's Restricted Stock/Unit award activity during the years ended December 31, 2014 , 2015 and 2016 follows: Shares/Units Weighted Average Grant-Date Fair Value Unvested at December 31, 2013 164,492 $ 26.94 Granted 90,181 40.07 Vested (56,307 ) 24.81 Forfeited (3,260 ) 31.00 Unvested at December 31, 2014 195,106 32.83 Granted 155,183 45.59 Vested (109,416 ) 30.28 Forfeited (9,311 ) 39.07 Unvested at December 31, 2015 231,562 42.33 Granted 177,775 41.74 Vested (104,297 ) 41.47 Forfeited (14,321 ) 42.54 Unvested at December 31, 2016 290,719 42.26

REGULATORY CAPITAL REQUIREMEN45

REGULATORY CAPITAL REQUIREMENTS (Tables)	12 Months Ended
	Dec. 31, 2016
Regulatory Capital Requirements [Abstract]
Schedule of the Regulatory Capital Ratios and Minimum Regulatory Requirements	The following table shows the regulatory capital ratios of the Company and the Banks and the minimum regulatory requirements (dollars in thousands): Actual Minimum for Capital Adequacy Purposes Minimum to be Categorized as “Well-Capitalized” Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio December 31, 2016: The Company—consolidated: Total capital to risk-weighted assets $ 1,214,913 13.40 % $ 725,566 8.00 % $ 906,957 10.00 % Tier 1 capital to risk-weighted assets 1,125,267 12.41 544,174 6.00 544,174 6.00 Tier 1 common equity to risk-weighted assets 1,014,994 11.19 408,131 4.50 n/a n/a Tier 1 capital to average leverage assets 1,125,267 11.83 380,519 4.00 n/a n/a Banner Bank: Total capital to risk- weighted assets 1,043,837 11.76 709,882 8.00 887,352 10.00 Tier 1 capital to risk- weighted assets 956,298 10.78 532,411 6.00 709,882 8.00 Tier 1 common equity to risk-weighted assets 956,298 10.78 399,308 4.50 576,779 6.50 Tier 1 capital to average leverage assets 956,298 10.34 369,936 4.00 462,420 5.00 Islanders Bank: Total capital to risk- weighted assets 35,207 18.43 15,281 8.00 19,101 10.00 Tier 1 capital to risk- weighted assets 33,099 17.33 11,461 6.00 15,281 8.00 Tier 1 common equity to risk-weighted assets 33,099 17.33 8,598 4.50 12,416 6.50 Tier 1 capital to average leverage assets 33,099 12.72 10,405 4.00 13,006 5.00 December 31, 2015: The Company—consolidated: Total capital to risk-weighted assets $ 1,139,554 13.63 % $ 668,941 8.00 % $ 836,530 10.00 % Tier 1 capital to risk-weighted assets 1,057,597 12.65 501,706 6.00 501,918 6.00 Tier 1 common equity to risk-weighted assets 1,013,971 12.13 376,279 4.50 n/a n/a Tier 1 capital to average leverage assets 1,057,597 11.06 382,617 4.00 n/a n/a Banner Bank: Total capital to risk- weighted assets 1,030,601 12.61 653,606 8.00 817,008 10.00 % Tier 1 capital to risk- weighted assets 950,865 11.64 490,205 6.00 653,606 8.00 Tier 1 common equity to risk-weighted assets 950,865 11.64 367,653 4.50 531,055 6.50 Tier 1 capital to average leverage assets 950,865 10.23 371,807 4.00 464,759 5.00 Islanders Bank: Total capital to risk- weighted assets 38,448 20.31 15,146 8.00 18,932 10.00 Tier 1 capital to risk- weighted assets 36,227 19.14 11,359 6.00 15,146 8.00 Tier 1 common equity to risk-weighted assets 36,227 19.14 8,520 4.50 12,306 6.50 Tier 1 capital to average leverage assets 36,227 13.38 10,826 4.00 13,533 5.00

GOODWILL, OTHER INTANGIBLE AS46

GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Tables)	12 Months Ended
	Dec. 31, 2016
Other Intangible Assets and Mortgage Servicing Rights [Abstract]
Schedule of Changes in Goodwill and Intangible Assets	The following table summarizes the changes in the Company’s goodwill, CDI and LHI for the years ended December 31, 2014 , 2015 and 2016 (in thousands): Goodwill CDI LHI Total Balance, December 31, 2013 $ — $ 2,449 $ — $ 2,449 Additions through acquisition — 2,372 — 2,372 Amortization — (1,990 ) — (1,990 ) Balance, December 31, 2014 — 2,831 — 2,831 Additions through acquisition 247,738 37,395 776 285,909 Amortization — (3,164 ) (66 ) (3,230 ) Other Changes (1) — (300 ) — (300 ) Balance, December 31, 2015 247,738 36,762 710 285,210 Amortization — (7,061 ) (249 ) (7,310 ) Adjustments to goodwill (3,155 ) — — (3,155 ) Balance, December 31, 2016 $ 244,583 $ 29,701 $ 461 $ 274,745 (1) Acquired CDI from Starbuck was adjusted for a branch that was subsequently sold.
Schedule of Estimated Annual Amortization Expense	Estimated amortization expense in future years with respect to CDI as of December 31, 2016 (in thousands): Year ended: Estimated Amortization 2017 $ 6,332 2018 5,609 2019 4,889 2020 4,169 Thereafter 8,702 Net carrying amount $ 29,701
Schedule of Mortgage Servicing Rights at Amortized Value	An analysis of the mortgage servicing rights for the years ended December 31, 2016 , 2015 and 2014 is presented below (in thousands): Years Ended December 31 2016 2015 2014 Balance, beginning of the year $ 13,295 $ 9,030 $ 8,086 Amounts capitalized 5,965 5,313 3,023 Additions through acquisition — 2,172 — Amortization (1) (4,011 ) (3,220 ) (2,079 ) Balance, end of the year (2) $ 15,249 $ 13,295 $ 9,030 (1) Amortization of mortgage servicing rights is recorded as a reduction of loan servicing income and any unamortized balance is fully written off if the loan repays in full. (2) There was no valuation allowance as of December 31, 2016 , 2015 and 2014 .

FAIR VALUE OF FINANCIAL INSTR47

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Financial Instruments, by Balance Sheet Grouping	The following table presents estimated fair values of the Company’s financial instruments as of December 31, 2016 and 2015 , whether or not recognized or recorded in the Consolidated Statements of Financial Condition (in thousands): December 31, 2016 December 31, 2015 Level Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Assets: Cash and due from banks 1 $ 247,719 $ 247,719 $ 261,917 $ 261,917 Securities—trading 2,3 24,568 24,568 34,134 34,134 Securities—available-for-sale 2 800,917 800,917 1,138,573 1,138,573 Securities—held-to-maturity 2,3 267,873 270,528 220,666 226,627 Loans receivable held for sale 2 246,353 246,815 44,712 45,600 Loans receivable 3 7,451,148 7,337,608 7,314,504 7,084,631 FHLB stock 3 12,506 12,506 16,057 16,057 BOLI 1 158,936 158,936 156,865 156,865 Mortgage servicing rights 3 15,249 16,740 13,295 17,370 Derivatives: Interest rate swaps 2 8,330 8,330 11,984 11,984 Interest rate lock and forward sales commitments 2 482 482 471 471 Liabilities: Demand, interest-bearing checking and money market 2 5,552,690 5,552,690 5,416,556 5,416,556 Regular savings 2 1,523,391 1,523,391 1,284,642 1,284,642 Certificates of deposit 2 1,045,333 1,028,866 1,353,870 1,332,825 Advances from FHLB at fair value 2 54,216 54,216 133,381 133,381 Junior subordinated debentures at fair value 3 95,200 95,200 92,480 92,480 Other borrowings 2 105,685 105,685 98,325 98,325 Derivatives: Interest rate swaps 2 8,330 8,330 11,984 11,984 Interest rate lock and forward sales commitments 2 289 289 50 50
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present financial assets and liabilities measured at fair value on a recurring basis and the level within the fair value hierarchy of the fair value measurements for those assets and liabilities as of December 31, 2016 and 2015 (in thousands): December 31, 2016 Level 1 Level 2 Level 3 Total Assets: Securities—trading U.S. Government and agency $ — $ 1,326 $ — $ 1,326 Municipal bonds — 335 — 335 Corporate Bonds (TPS securities) — — 21,143 21,143 Mortgage-backed securities — 1,641 — 1,641 Equity securities — 123 — 123 — 3,425 21,143 24,568 Securities—available-for-sale U.S. Government and agency $ — $ 56,978 $ — $ 56,978 Municipal bonds — 109,853 — 109,853 Corporate bonds — 10,283 — 10,283 Mortgage-backed securities — 594,712 — 594,712 Asset-backed securities — 28,993 — 28,993 Equity securities — 98 — 98 — 800,917 — 800,917 Loans held for sale — 9,600 — 9,600 Derivatives Interest rate lock and forward sales commitments — 482 — 482 Interest rate swaps — 8,330 — 8,330 $ — $ 822,754 $ 21,143 $ 843,897 Liabilities Advances from FHLB at fair value $ — $ 54,216 $ — $ 54,216 Junior subordinated debentures at fair value — — 95,200 95,200 Derivatives Interest rate lock and forward sales commitments — 289 — 289 Interest rate swaps — 8,330 — 8,330 $ — $ 62,835 $ 95,200 $ 158,035 December 31, 2015 Level 1 Level 2 Level 3 Total Assets: Securities—trading U.S. Government and agency $ — $ 1,368 $ — $ 1,368 Municipal bonds — 341 — 341 Corporate Bonds (TPS securities) — — 18,699 18,699 Mortgage-backed securities — 13,663 — 13,663 Equity securities — 63 — 63 — 15,435 18,699 34,134 Securities—available-for-sale U.S. Government and agency $ — $ 30,231 $ — $ 30,231 Municipal bonds — 143,319 — 143,319 Corporate bonds — 15,981 — 15,981 Mortgage-backed securities — 918,259 — 918,259 Asset-backed securities — 30,685 — 30,685 Equity securities — 98 — 98 — 1,138,573 — 1,138,573 Derivatives Interest rate lock and forward sales commitments — 471 — 471 Interest rate swaps — 11,984 — 11,984 $ — $ 1,166,463 $ 18,699 $ 1,185,162 Liabilities Advances from FHLB at fair value $ — $ 133,381 $ — $ 133,381 Junior subordinated debentures at fair value — — 92,480 92,480 Derivatives Interest rate lock and forward sales commitments — 50 — 50 Interest rate swaps — 11,984 — 11,984 $ — $ 145,415 $ 92,480 $ 237,895
Schedule of Valuation Technique, Unobservable Input, and Qualitative Information for Unobservable Inputs	The following table provides a description of the valuation technique, unobservable inputs, and qualitative information about the unobservable inputs for the Company's assets and liabilities classified as Level 3 and measured at fair value on a recurring and nonrecurring basis at December 31, 2016 : December 31 2016 Financial Instruments Valuation Technique Unobservable Inputs Weighted Average Rate Corporate Bonds (TPS securities) Discounted cash flows Discount rate 6.00 % Junior subordinated debentures Discounted cash flows Discount rate 6.00 % REO Appraisals Discount to appraised value 0% to 45%
Schedule of Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	The following table provides a reconciliation of the assets and liabilities measured at fair value using significant unobservable inputs (Level 3) on a recurring basis during the year ended December 31, 2016 and 2015 (in thousands): Year Ended December 31, 2016 Level 3 Fair Value Inputs TPS Securities Borrowings— Junior Subordinated Debentures Beginning balance at December 31, 2015 $ 18,699 $ 92,480 Total gains or losses recognized Assets gains 719 — Liabilities losses — 2,720 Purchases, issuances and settlements, net 1,725 — Paydowns and maturities — — Transfers in and/or out of Level 3 — — Ending balance at December 31, 2016 $ 21,143 $ 95,200 Year Ended December 31, 2015 Level 3 Fair Value Inputs TPS and TRUP CDOs Borrowings— Junior Subordinated Debentures Beginning balance at December 31, 2014 $ 19,119 $ 78,001 Total gains or losses recognized Assets gains 537 — Liabilities losses — 2,714 Purchases, issuances and settlements 5,697 11,765 Paydowns and maturities (6,654 ) — Ending balance at December 31, 2015 $ 18,699 $ 92,480
Schedule of Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis	The following table presents financial assets and liabilities measured at fair value on a non-recurring basis and the level within the fair value hierarchy of the fair value measurements for those assets at December 31, 2016 and 2015 (in thousands): December 31, 2016 Level 1 Level 2 Level 3 Total REO $ — $ — $ 11,081 $ 11,081 December 31, 2015 Level 1 Level 2 Level 3 Total Impaired loans $ — $ — $ 2,372 $ 2,372 REO — — 11,627 11,627 The following table presents the losses resulting from non-recurring fair value adjustments for the years ended December 31, 2016 and 2015 (in thousands): For the year ended December 31, 2016 2015 Impaired loans $ (182 ) $ (110 ) REO (671 ) (231 ) Total loss from nonrecurring measurements $ (853 ) $ (341 )

BANNER CORPORATION (PARENT CO48

BANNER CORPORATION (PARENT COMPANY ONLY) (Tables)	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Condensed Financial Condition	Summary financial information is as follows (in thousands): Statements of Financial Condition December 31 2016 2015 ASSETS Cash $ 86,268 $ 58,232 Investment in trust equities 4,212 4,212 Investment in subsidiaries 1,307,475 1,319,348 Other assets 13,784 21,134 Total assets $ 1,411,739 $ 1,402,926 LIABILITIES AND SHAREHOLDERS’ EQUITY Miscellaneous liabilities $ 8,990 $ 7,846 Deferred tax liability 1,839 2,541 Junior subordinated debentures at fair value 95,200 92,480 Shareholders’ equity 1,305,710 1,300,059 Total liabilities and shareholders' equity $ 1,411,739 $ 1,402,926
Schedule of Condensed Statement of Operations	Statements of Operations Years Ended December 31 2016 2015 2014 INTEREST INCOME: Interest-bearing deposits $ 127 $ 122 $ 96 OTHER INCOME (EXPENSE): Dividend income from subsidiaries 50,971 170,260 26,027 Equity in undistributed (distributions in excess of) income of subsidiaries 40,852 (116,120 ) 33,612 Other income 60 69 67 Net change in valuation of financial instruments carried at fair value (2,720 ) (2,714 ) (4,073 ) Interest on other borrowings (4,040 ) (3,247 ) (2,914 ) Other expenses (3,450 ) (7,175 ) (2,519 ) Net income before taxes 81,800 41,195 50,296 BENEFIT FROM INCOME TAXES (3,585 ) (4,027 ) (3,774 ) NET INCOME $ 85,385 $ 45,222 $ 54,070
Schedule of Condensed Statement of Cash Flows	Statements of Cash Flows Years Ended December 31 2016 2015 2014 OPERATING ACTIVITIES: Net income $ 85,385 $ 45,222 $ 54,070 Adjustments to reconcile net income to net cash provided by operating activities: Distributions in excess of (equity in undistributed) income of subsidiaries (40,852 ) 116,120 (33,612 ) Decrease in deferred taxes (702 ) (1,398 ) (1,444 ) Net change in valuation of financial instruments carried at fair value 2,720 2,714 4,073 Decrease (increase) in other assets 7,332 (10,655 ) (3,822 ) Increase in other liabilities 3,233 3,919 222 Net cash provided from operating activities 57,116 155,922 19,487 INVESTING ACTIVITIES: Funds transferred to deferred compensation trust (26 ) (26 ) (26 ) Reduction in investment in subsidiaries 50,000 — — Acquisitions — (132,652 ) — Net cash provided from (used by) investing activities 49,974 (132,678 ) (26 ) FINANCING ACTIVITIES: Issuance of stock for shareholder reinvestment program — 34 127 Repurchase of common stock (50,772 ) — — Cash dividends paid (28,282 ) (17,170 ) (13,462 ) Net cash used by financing activities (79,054 ) (17,136 ) (13,335 ) NET CHANGE IN CASH 28,036 6,108 6,126 CASH, BEGINNING OF PERIOD 58,232 52,124 45,998 CASH, END OF PERIOD $ 86,268 $ 58,232 $ 52,124

CALCULATION OF EARNINGS PER C49

CALCULATION OF EARNINGS PER COMMON SHARE (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Weighted Shares Outstanding	The following tables show the calculation of earnings per common share (in thousands, except per share data): Years Ended December 31 2016 2015 2014 Net income $ 85,385 $ 45,222 $ 54,070 Weighted average number of common shares outstanding Basic 33,820,148 23,801,373 19,359,409 Diluted 33,853,511 23,866,621 19,402,656 Earnings per common share Basic $ 2.52 $ 1.90 $ 2.79 Diluted $ 2.52 $ 1.89 $ 2.79

SELECTED QUARTERLY FINANCIAL 50

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2016
Selected Quarterly Financial Information [Abstract]
Schedule of Quarterly Financial Information	Results of operations on a quarterly basis for the years ended December 31, 2016 , 2015 and 2014 were as follows (dollars in thousands except for per share data): Year Ended December 31, 2016 First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 95,301 $ 97,321 $ 97,849 $ 101,007 Interest expense 4,258 4,173 4,141 3,836 Net interest income before provision for loan losses 91,043 93,148 93,708 97,171 Provision for loan losses — 2,000 2,000 2,030 Net interest income 91,043 91,148 91,708 95,141 Non-interest income 19,959 20,537 23,512 19,463 Non-interest expense 84,034 79,887 79,092 79,857 Income before provision for income taxes 26,968 31,798 36,128 34,747 Provision for income taxes 9,194 10,841 12,277 11,943 Net income $ 17,774 $ 20,957 $ 23,851 $ 22,804 Basic earnings per share $ 0.52 $ 0.62 $ 0.70 $ 0.69 Diluted earnings per share 0.52 0.61 0.70 0.69 Dividends declared 0.21 0.21 0.23 0.23 Year Ended December 31, 2015 First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 49,069 $ 54,076 $ 54,793 $ 96,495 Interest expense 2,533 2,619 2,605 4,396 Net interest income before provision for loan losses 46,536 51,457 52,188 92,099 Provision for loan losses — — — — Net interest income 46,536 51,457 52,188 92,099 Non-interest income 13,696 16,141 14,098 18,356 Non-interest expense 41,914 47,734 46,697 100,254 Income before provision for income taxes 18,318 19,864 19,589 10,201 Provision for income taxes 6,184 6,615 6,642 3,308 Net income $ 12,134 $ 13,249 $ 12,947 $ 6,893 Basic earnings per share $ 0.61 $ 0.64 $ 0.62 $ 0.20 Diluted earnings per share 0.61 0.64 0.62 0.20 Dividends declared 0.18 0.18 0.18 0.18 Year Ended December 31, 2014 First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 45,106 $ 46,540 $ 49,764 $ 49,251 Interest expense 2,767 2,732 2,700 2,590 Net interest income before provision for loan losses 42,339 43,808 47,064 46,661 Provision for loan losses — — — — Net interest income 42,339 43,808 47,064 46,661 Non-interest income 9,032 20,310 13,536 12,113 Non-interest expense 35,581 38,435 38,495 41,230 Income before provision for income taxes 15,790 25,683 22,105 17,544 Provision for income taxes 5,241 8,696 7,284 5,831 Net income $ 10,549 $ 16,987 $ 14,821 $ 11,713 Basic earnings per share $ 0.55 $ 0.88 $ 0.76 $ 0.60 Diluted earnings per share 0.54 0.88 0.76 0.60 Dividends declared 0.18 0.18 0.18 0.18

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Schedule of Fair Value, Off-balance Sheet Risks [Table Text Block]	Outstanding commitments for which no asset or liability for the notional amount has been recorded consisted of the following at the dates indicated (in thousands): Contract or Notional Amount December 31, 2016 December 31, 2015 Commitments to extend credit $ 2,204,795 $ 2,132,996 Standby letters of credit and financial guarantees 17,694 22,315 Commitments to originate loans 69,833 32,908 Risk participation agreement 7,488 7,672 Derivatives also included in Note 24: Commitments to originate loans held for sale 69,487 76,146 Commitments to sell loans secured by one- to four-family residential properties 36,907 37,545 Commitments to sell securities related to mortgage banking activities 44,000 41,500

DERIVATIVES AND HEDGING DERIV52

DERIVATIVES AND HEDGING DERIVATIVES AND HEDGING (Tables)	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	As of December 31, 2016 and December 31, 2015 , the notional values or contractual amounts and fair values of the Company's derivatives designated in hedge relationships were as follows (in thousands): Asset Derivatives Liability Derivatives December 31, 2016 December 31, 2015 December 31, 2016 December 31, 2015 Notional/ Contract Amount Fair Value (1) Notional/ Contract Amount Fair Value (1) Notional/ Contract Amount Fair Value (2) Notional/ Contract Amount Fair Value (2) Interest rate swaps $ 5,855 $ 660 $ 6,734 $ 938 $ 5,855 $ 660 $ 6,734 $ 938 (1) Included in Loans Receivable on the Consolidated Statements of Financial Condition. (2) Included in Other Liabilities on the Consolidated Statements of Financial Condition.
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location	As of December 31, 2016 and December 31, 2015 , the notional values or contractual amounts and fair values of the Company's derivatives not designated in hedge relationships were as follows (in thousands): Asset Derivatives Liability Derivatives December 31, 2016 December 31, 2015 December 31, 2016 December 31, 2015 Notional/ Contract Amount Fair Value (1) Notional/ Contract Amount Fair Value (1) Notional/ Contract Amount Fair Value (2) Notional/ Contract Amount Fair Value (2) Interest rate swaps $ 309,936 $ 7,670 $ 293,937 $ 11,046 $ 309,936 $ 7,670 $ 293,937 $ 11,046 Mortgage loan commitments 42,296 30 76,146 428 27,191 174 — — Forward sales contracts 71,192 452 41,500 43 9,715 115 32,763 50 $ 423,424 $ 8,152 $ 411,583 $ 11,517 $ 346,842 $ 7,959 $ 326,700 $ 11,096 (1) Included in Other Assets on the Consolidated Statements of Financial Condition, with the exception of those interest rate swaps from prior to 2009 that were not designated in hedge relationships (with a fair value of $822,000 at December 31, 2016 and $327,000 at December 31, 2015 ), which are included in Loans Receivable. (2) Included in Other Liabilities on the Consolidated Statements of Financial Condition. Gains (losses) recognized in income on non-designated hedging instruments for the years ended December 31, 2016 and 2015 were as follows (in thousands): For the Year Ended December 31, Location on Income Statement 2016 2015 Mortgage loan commitments Mortgage banking operations $ (348 ) $ 100 Forward sales contracts Mortgage banking operations 296 141 $ (52 ) $ 241
Offsetting Assets and Liabilities	The following table illustrates the potential effect of the Company's derivative master netting arrangements, by type of financial instrument, on the Company's Consolidated Statements of Financial Condition as of December 31, 2016 and December 31, 2015 (in thousands): December 31, 2016 Gross Amounts of Financial Instruments Not Offset in the Statement of Financial Condition Gross Amounts Recognized Amounts offset in the Statement of Financial Condition Net Amounts in the Statement of Financial Condition Netting Adjustment Per Applicable Master Netting Agreements Fair Value of Financial Collateral in the Statement of Financial Condition Net Amount Derivative assets Interest rate swaps $ 8,330 $ — $ 8,330 $ (362 ) $ — $ 7,968 $ 8,330 $ — $ 8,330 $ (362 ) $ — $ 7,968 Derivative liabilities Interest rate swaps $ 8,330 $ — $ 8,330 $ (362 ) $ (7,557 ) $ 411 $ 8,330 $ — $ 8,330 $ (362 ) $ (7,557 ) $ 411 December 31, 2015 Gross Amounts of Financial Instruments Not Offset in the Statement of Financial Condition Gross Amounts Recognized Amounts offset in the Statement of Financial Condition Net Amounts in the Statement of Financial Condition Netting Adjustment Per Applicable Master Netting Agreements Fair Value of Financial Collateral in the Statement of Financial Condition Net Amount Derivative assets Interest rate swaps $ 11,984 $ — $ 11,984 $ — $ — $ 11,984 $ 11,984 $ — $ 11,984 $ — $ — $ 11,984 Derivative liabilities Interest rate swaps $ 11,984 $ — $ 11,984 $ — $ (11,984 ) $ — $ 11,984 $ — $ 11,984 $ — $ (11,984 ) $ —

BASIS OF PRESENTATION AND SUM53

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Investment in FHLB Stock) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Gain (Loss) on Investments [Line Items]
Federal Home Loan Bank (FHLB) stock	$ 12,506	$ 16,057
Federal Home Loan Bank Stock, Par Value Per Share	$ 100
Investment in Federal Home Loan Bank Stock [Member]
Gain (Loss) on Investments [Line Items]
Other than Temporary Impairment Losses, Investments	$ 0

BASIS OF PRESENTATION AND SUM54

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Property, Plant and Equipment Useful Lives) (Details)	12 Months Ended
	Dec. 31, 2016
Buildings and leased improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	10 years
Buildings and leased improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	30 years
Furniture and equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Furniture and equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	10 years

BASIS OF PRESENTATION AND SUM55

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Textuals) (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2016USD ($)subsidiaryofficelocation
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Number of wholly-owned subsidiaries | subsidiary		2
Subsidiary, Banner Bank [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Number of offices | office		187
Number of production offices | office		11
Subsidiary, Islanders Bank [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Number of locations | location		3
Minimum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Intangible asset, useful life		3 years
Minimum [Member] | Core Deposit Intangibles [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Intangible asset, useful life	3 years
Maximum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Intangible asset, useful life		10 years
Maximum [Member] | Core Deposit Intangibles [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Intangible asset, useful life		10 years
Loans Receivable [Member] | Interest Rate Swap [Member] | F&M Bank [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Derivative Asset, Notional Amount | $		$ 8.7
Other assets [Member] | Interest Rate Swap [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Derivative Asset, Notional Amount | $		$ 307.1

BUSINESS COMBINATIONS BUSINES56

BUSINESS COMBINATIONS BUSINESS COMBINATIONS (Textual) (Details) $ / shares in Units, shares in Thousands, $ in Thousands	Oct. 01, 2015USD ($)bank_branchshares	Mar. 06, 2015USD ($)$ / shares	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Business Acquisition [Line Items]
Assets	$ 9,900,000		$ 9,793,668	$ 9,796,298
Number of Branches | bank_branch	203
Goodwill			$ 244,583	$ 247,738	$ 0	$ 0
Starbuck Bancshares, Inc [Member]
Business Acquisition [Line Items]
Effective date of acquisition	Oct. 1, 2015
Cash paid	$ 130,000
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable, Shares | shares	13,230
Business Combination, Acquired Assets	$ 4,459,985
Business Combination, Acquired Deposits	3,638,596
Business Combination, Acquired Receivables	2,999,130
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	33,500
Goodwill	$ 222,892
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years
Business Combination, Acquired Receivables, Non-Credit-Impaired	$ 2,950,000
Business Combination, Acquired Receivables, Non-Credit-Impaired, Fair Value	2,940,000
Business Combination, Acquired Receivables, Discount	17,700
Business Combination, Acquired Receivables, Non-Credit-Impaired, Cash Flows Not Expected to be Collected at Acquisition	44,100
Property and equipment	66,728
Cash and cash equivalents	$ 95,821
Siuslaw Financial Group, Inc [Member]
Business Acquisition [Line Items]
Effective date of acquisition		Mar. 6, 2015
Cash paid		$ 5,806
Business Combination, Acquired Assets		369,763
Business Combination, Acquired Deposits		316,406
Business Combination, Acquired Receivables		247,098
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		3,895
Goodwill		$ 21,691
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		8 years
Business Combination, Acquired Receivables, Non-Credit-Impaired		$ 244,200
Business Combination, Acquired Receivables, Non-Credit-Impaired, Fair Value		241,400
Business Combination, Acquired Receivables, Discount		$ 2,800
Business Acquisition, Equity Interest Issued to Acquiree's Shareholders, Per Share | $ / shares		$ 0.32231
Business Acquisition, Cash Payment Issued to Acquiree's Shareholders, Per Share | $ / shares		$ 1.41622
Property and equipment		$ 8,127
Cash and cash equivalents		$ 84,405
Washington, Oregon, Idaho, California and Utah [Member] | Starbuck Bancshares, Inc [Member]
Business Acquisition [Line Items]
Business Combination, Number of Branches | bank_branch	98

BUSINESS COMBINATIONS BUSINES57

BUSINESS COMBINATIONS BUSINESS COMBINATIONS (Schedule of Components of Acquisition) (Details) - USD ($) $ in Thousands	Oct. 01, 2015	Mar. 06, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jun. 20, 2014	Dec. 31, 2013
LIABILITIES
Goodwill			$ 244,583	$ 247,738	$ 0		$ 0
Starbuck Bancshares, Inc [Member]
Business Acquisition [Line Items]
Effective date of acquisition	Oct. 1, 2015
Cash paid	$ 130,000
Fair value of common shares issued	630,674
Total consideration	760,674
ASSETS
Cash and cash equivalents	95,821
Securities	1,037,238
Loans receivable	2,999,130
REO, held for sale	6,105
Property and equipment	66,728
CDI	33,500
Deferred tax asset	108,454
Other assets	113,009
Total assets acquired	4,459,985
LIABILITIES
Deposits	3,638,596
FHLB advances	221,442
Junior subordinated debentures	5,806
Other liabilities	56,359
Total liabilities assumed	3,922,203
Net assets acquired	537,782
Goodwill	222,892
Contractual amount of acquired loans	$ 3,040,000
Siuslaw Financial Group, Inc [Member]
Business Acquisition [Line Items]
Effective date of acquisition		Mar. 6, 2015
Cash paid		$ 5,806
Fair value of common shares issued		58,100
Total consideration		63,906
ASSETS
Cash and cash equivalents		84,405
Securities		12,865
Loans receivable		247,098
REO, held for sale		2,525
Property and equipment		8,127
CDI		3,895
Other assets		10,848
Total assets acquired		369,763
LIABILITIES
Deposits		316,406
Junior subordinated debentures		5,959
Other liabilities		5,183
Total liabilities assumed		327,548
Net assets acquired		42,215
Goodwill		21,691
Contractual amount of acquired loans		$ 252,200
Six Oregon Branches [Member]
LIABILITIES
Contractual amount of acquired loans						$ 88,300

BUSINESS COMBINATIONS (Acquired

BUSINESS COMBINATIONS (Acquired PCI Loans) (Details) - USD ($) $ in Thousands	Oct. 01, 2015	Mar. 06, 2015
Starbuck Bancshares, Inc [Member]
Business Acquisition [Line Items]
Contractually required principal and interest payments	$ 98,746
Nonaccretable difference	(26,162)
Cash flows expected to be collected	72,584
Accretable yield	(11,071)
Fair value of PCI loans	$ 61,513
Siuslaw Financial Group, Inc [Member]
Business Acquisition [Line Items]
Contractually required principal and interest payments		$ 11,134
Nonaccretable difference		(3,238)
Cash flows expected to be collected		7,896
Accretable yield		(2,239)
Fair value of PCI loans		$ 5,657

BUSINESS COMBINATIONS (Pro Form

BUSINESS COMBINATIONS (Pro Forma Information) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)$ / shares
Starbuck Bancshares, Inc [Member]
Business Acquisition [Line Items]
Total revenues (net interest income plus non-interest income) | $	$ 455,427
Net income | $	$ 86,255
Earnings per share - basic (usd per share) | $ / shares	$ 2.56
Earnings per share - diluted (usd per share) | $ / shares	$ 2.55
Siuslaw Financial Group, Inc [Member]
Business Acquisition [Line Items]
Total revenues (net interest income plus non-interest income) | $	$ 308,153
Net income | $	$ 44,484
Earnings per share - basic (usd per share) | $ / shares	$ 1.85
Earnings per share - diluted (usd per share) | $ / shares	$ 1.85

BUSINESS COMBINATIONS BUSINES60

BUSINESS COMBINATIONS BUSINESS COMBINATIONS (Schedule of Acquisition Related Costs) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Acquisition related costs		$ 11,733	$ 26,110	$ 4,325
Six Oregon Branches [Member]
Business Acquisition [Line Items]
Acquisition related costs	$ 0	0		1,784
Siuslaw Financial Group, Inc [Member]
Business Acquisition [Line Items]
Acquisition related costs		95	2,000	748
Starbuck Bancshares, Inc [Member]
Business Acquisition [Line Items]
Acquisition related costs		11,638	24,110	1,793
Salary and Employee Benefits [Member]
Business Acquisition [Line Items]
Acquisition related costs		1,384	6,577	0
Occupancy and Equipment [Member]
Business Acquisition [Line Items]
Acquisition related costs		2,590	1,031	105
Advertising and Marketing [Member]
Business Acquisition [Line Items]
Acquisition related costs		1,158	527	327
Information and Computer Data Services [Member]
Business Acquisition [Line Items]
Acquisition related costs		2,490	2,875	334
Payment and Card Processing Expenses [Member]
Business Acquisition [Line Items]
Acquisition related costs		197	28	185
Professional Services [Member]
Business Acquisition [Line Items]
Acquisition related costs		2,230	11,169	2,953
Miscellaneous Other Noninterest Expense [Member]
Business Acquisition [Line Items]
Acquisition related costs		$ 1,684	$ 3,903	$ 421

SECURITIES (Schedule of Securit

SECURITIES (Schedule of Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Trading:
Trading Securities, Amortized Cost	$ 30,154	$ 39,344
Trading Securities, Fair Value	24,568	34,134
Available-for-Sale:
Available-for-sale Securities, Amortized Cost	806,336	1,139,740
Gross Unrealized Gains	2,752	5,188
Gross Unrealized Losses	(8,171)	(6,355)
Securities—available-for-sale	800,917	1,138,573
Held-to-Maturity:
Held-to-maturity Securities, Amortized Cost	267,873	220,666
Gross Unrealized Gains	4,482	6,477
Gross Unrealized Losses	(1,827)	(516)
Held-to-maturity Securities, Fair Value	270,528	226,627
U.S. Government and agency obligations
Trading:
Trading Securities, Amortized Cost	1,230	1,230
Trading Securities, Fair Value	1,326	1,368
Available-for-Sale:
Available-for-sale Securities, Amortized Cost	57,288	30,211
Gross Unrealized Gains	146	213
Gross Unrealized Losses	(456)	(193)
Securities—available-for-sale	56,978	30,231
Held-to-Maturity:
Held-to-maturity Securities, Amortized Cost	1,065	1,106
Gross Unrealized Gains	0	5
Gross Unrealized Losses	(18)	0
Held-to-maturity Securities, Fair Value	1,047	1,111
Municipal bonds
Trading:
Trading Securities, Amortized Cost	331	332
Trading Securities, Fair Value	335	341
Available-for-Sale:
Available-for-sale Securities, Amortized Cost	110,487	142,898
Gross Unrealized Gains	455	853
Gross Unrealized Losses	(1,089)	(432)
Securities—available-for-sale	109,853	143,319
Held-to-Maturity:
Held-to-maturity Securities, Amortized Cost	196,989	162,778
Gross Unrealized Gains	4,173	6,219
Gross Unrealized Losses	(1,272)	(191)
Held-to-maturity Securities, Fair Value	199,890	168,806
Corporate bonds
Trading:
Trading Securities, Amortized Cost	26,959	25,063
Trading Securities, Fair Value	21,143	18,699
Available-for-Sale:
Available-for-sale Securities, Amortized Cost	10,255	15,937
Gross Unrealized Gains	77	56
Gross Unrealized Losses	(49)	(12)
Securities—available-for-sale	10,283	15,981
Held-to-Maturity:
Held-to-maturity Securities, Amortized Cost	3,876	4,273
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Held-to-maturity Securities, Fair Value	3,876	4,273
Mortgage-backed or related securities
Trading:
Trading Securities, Amortized Cost	1,620	12,705
Trading Securities, Fair Value	1,641	13,663
Available-for-Sale:
Available-for-sale Securities, Amortized Cost	598,899	919,318
Gross Unrealized Gains	2,064	4,056
Gross Unrealized Losses	(6,251)	(5,115)
Securities—available-for-sale	594,712	918,259
Held-to-Maturity:
Held-to-maturity Securities, Amortized Cost	65,943	52,509
Gross Unrealized Gains	309	253
Gross Unrealized Losses	(537)	(325)
Held-to-maturity Securities, Fair Value	65,715	52,437
Asset-backed securities
Available-for-Sale:
Available-for-sale Securities, Amortized Cost	29,319	31,288
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(326)	(603)
Securities—available-for-sale	28,993	30,685
Equity securities
Trading:
Trading Securities, Amortized Cost	14	14
Trading Securities, Fair Value	123	63
Available-for-Sale:
Available-for-sale Securities, Amortized Cost	88	88
Gross Unrealized Gains	10	10
Gross Unrealized Losses	0	0
Securities—available-for-sale	$ 98	$ 98

SECURITIES (Securities with Con

SECURITIES (Securities with Continuous Loss Position) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Available-for-Sale:
Less than 12 Months, Fair Value	$ 518,373	$ 637,744
Less than 12 Months, Unrealized Losses	(7,283)	(5,270)
12 Months or More, Fair Value	68,099	89,748
12 Months or More, Unrealized Losses	(888)	(1,085)
Total Fair Value	586,472	727,492
Total Unrealized Losses	(8,171)	(6,355)
Held-to-Maturity:
Less Than 12 Months, Fair Value	108,094	63,038
Less Than 12 Months, Unrealized Losses	(1,822)	(511)
12 Months or More, Fair Value	204	509
12 Months or More, Unrealized Losses	(5)	(5)
Total Fair Value	108,298	63,547
Total Unrealized Losses	(1,827)	(516)
U.S. Government and agency obligations
Available-for-Sale:
Less than 12 Months, Fair Value	39,043	8,707
Less than 12 Months, Unrealized Losses	(442)	(97)
12 Months or More, Fair Value	1,012	10,489
12 Months or More, Unrealized Losses	(14)	(96)
Total Fair Value	40,055	19,196
Total Unrealized Losses	(456)	(193)
Held-to-Maturity:
Less Than 12 Months, Fair Value	1,047
Less Than 12 Months, Unrealized Losses	(18)
12 Months or More, Fair Value	0
12 Months or More, Unrealized Losses	0
Total Fair Value	1,047
Total Unrealized Losses	(18)
Municipal bonds
Available-for-Sale:
Less than 12 Months, Fair Value	60,765	69,848
Less than 12 Months, Unrealized Losses	(1,087)	(426)
12 Months or More, Fair Value	556	905
12 Months or More, Unrealized Losses	(2)	(6)
Total Fair Value	61,321	70,753
Total Unrealized Losses	(1,089)	(432)
Held-to-Maturity:
Less Than 12 Months, Fair Value	64,802	28,545
Less Than 12 Months, Unrealized Losses	(1,267)	(188)
12 Months or More, Fair Value	204	254
12 Months or More, Unrealized Losses	(5)	(3)
Total Fair Value	65,006	28,799
Total Unrealized Losses	(1,272)	(191)
Corporate bonds
Available-for-Sale:
Less than 12 Months, Fair Value	5,206	5,153
Less than 12 Months, Unrealized Losses	(49)	(12)
12 Months or More, Fair Value	0	0
12 Months or More, Unrealized Losses	0	0
Total Fair Value	5,206	5,153
Total Unrealized Losses	(49)	(12)
Mortgage-backed or related securities
Available-for-Sale:
Less than 12 Months, Fair Value	403,431	533,143
Less than 12 Months, Unrealized Losses	(5,604)	(4,380)
12 Months or More, Fair Value	47,467	68,562
12 Months or More, Unrealized Losses	(647)	(735)
Total Fair Value	450,898	601,705
Total Unrealized Losses	(6,251)	(5,115)
Held-to-Maturity:
Less Than 12 Months, Fair Value	42,245	34,493
Less Than 12 Months, Unrealized Losses	(537)	(323)
12 Months or More, Fair Value	0	255
12 Months or More, Unrealized Losses	0	(2)
Total Fair Value	42,245	34,748
Total Unrealized Losses	(537)	(325)
Asset-backed securities
Available-for-Sale:
Less than 12 Months, Fair Value	9,928	20,893
Less than 12 Months, Unrealized Losses	(101)	(355)
12 Months or More, Fair Value	19,064	9,792
12 Months or More, Unrealized Losses	(225)	(248)
Total Fair Value	28,992	30,685
Total Unrealized Losses	$ (326)	$ (603)

SECURITIES (Securities Debt Mat

SECURITIES (Securities Debt Maturities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Amortized Cost
Maturing in one year or less	$ 1,751
Maturing after one year through five years	230
Maturing after five years through ten years	1,200
Maturing after ten years through twenty years	0
Maturing after twenty years	26,959
Total with Maturity Date	30,140
Equity securities	14
Trading Securities, Cost	30,154	$ 39,344
Fair Value
Maturing in one year or less	1,775
Maturing after one year through five years	231
Maturing after five years through ten years	1,296
Maturing after ten years through twenty years	0
Maturing after twenty years	21,143
Total with Maturity Date	24,445
Equity securities	123
Trading Securities, Fair Value	24,568	34,134
Amortized Cost
Maturing in one year or less	13,077
Maturing after one year through five years	120,405
Maturing after five years through ten years	176,010
Maturing after ten years through twenty years	188,557
Maturing after twenty years	308,199
Total with Maturity Date	806,248
Equity securities	88
Available-for-sale Securities, Amortized Cost	806,336	1,139,740
Fair Value
Maturing in one year or less	13,063
Maturing after one year through five years	120,126
Maturing after five years through ten years	173,720
Maturing after ten years through twenty years	187,940
Maturing after twenty years	305,970
Total with Maturity Date	800,819
Equity securities	98
Fair Value	800,917	1,138,573
Amortized Cost
Maturing in one year or less	1,962
Maturing after one year through five years	18,988
Maturing after five years through ten years	113,587
Maturing after ten years through twenty years	88,546
Maturing after twenty years	44,790
Held-to-maturity Securities	267,873	220,666
Fair Value
Maturing in one year or less	1,975
Maturing after one year through five years	19,000
Maturing after five years through ten years	114,336
Maturing after ten years through twenty years	91,098
Maturing after twenty years	44,119
Held-to-maturity Securities, Fair Value	$ 270,528	$ 226,627

SECURITIES (Securities Pledged)

SECURITIES (Securities Pledged) (Details) $ in Thousands	Dec. 31, 2016USD ($)
Pledged Financial Instruments, Not Separately Reported, Securities [Abstract]
State and local governments public deposits, carrying value	$ 203,510
Interest rate swap counterparties, carrying value	24,393
Repurchase transaction accounts, carrying value	114,949
Other, carrying value	1,778
Total pledged securities, carrying value	344,630
State and local governments public deposits, amortized cost	203,474
Interest rate swap counterparties, amortized cost	24,447
Repurchase transaction accounts, amortized cost	115,650
Other, amortized cost	1,782
Total pledged securities, amortized cost	345,353
State and local governments public deposits, fair value	207,013
Interest rate swap counterparties, fair value	24,287
Repurchase transaction accounts, fair value	114,864
Other, fair value	1,778
Total pledged securities, fair value	$ 347,942

SECURITIES (Textuals) (Details)

SECURITIES (Textuals) (Details)	12 Months Ended
	Dec. 31, 2016USD ($)security	Dec. 31, 2015USD ($)security	Dec. 31, 2014USD ($)security
Trading:
Trading securites, proceeds from sale	$ 7,839,000	$ 4,419,000	$ 2,387,000
Trading Securities, Realized Gain (Loss)	530,000	(690,000)	1,000
Trading securities, OTTI charges	$ 0	$ 0	$ 0
Trading securities, number of securities in nonaccrual status | security	0	0	0
Trading securities, unrealized holding gain	$ (376,000)	$ 2,000,000
Available-for-Sale:
Available-for-sale securities, unrealized loss position, number of securities | security	243	242	94
Available-for-sale securities, proceeds from sale	$ 369,800,000	$ 232,600,000	$ 56,300,000
Available-for-sale securities, Realized Gain (Loss)	311,000	126,000	41,000
Available-for-sale securities, OTTI charges	$ 0	$ 0	$ 0
Available-for-sale Securities, Number of Securities in Nonaccrual Status | security	0	0	0
Held-to-Maturity:
Held-to-maturity Securities, unrealized loss position, number of securities | security	73	32	25
Held-to-maturity Securities, proceeds from sale	$ 0	$ 0	$ 0
Held-to-maturity securities, number of securities in nonaccrual status | security	0	0	0

LOANS RECEIVABLE AND THE ALLO66

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Loans by Type) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 7,451,148	$ 7,314,504
Allowance for loan losses	85,997	78,008	$ 75,907
Total loans, net	$ 7,365,151	$ 7,236,496
Percent of total loans	100.00%	100.00%
Unearned loan fees in excess of unamortized costs	$ 5,800	$ (5,500)
Discount on acquired loans, net	31,100	43,700
Related party loans	4,300	7,900
Commerical real estate - owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 1,352,999	$ 1,327,807
Percent of total loans	18.10%	18.20%
Commerical real estate - investment properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 1,986,336	$ 1,765,353
Percent of total loans	26.70%	24.10%
Multifamily real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 248,150	$ 472,976
Allowance for loan losses	$ 1,360	$ 4,195	4,562
Percent of total loans	3.30%	6.50%
Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 124,068	$ 72,103
Percent of total loans	1.70%	1.00%
Multifamily construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 124,126	$ 63,846
Percent of total loans	1.70%	0.90%
One-to four-family construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 375,704	$ 278,469
Percent of total loans	5.00%	3.80%
Land and land development - residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 170,004	$ 126,773
Percent of total loans	2.30%	1.70%
Land and land development - commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 29,184	$ 33,179
Percent of total loans	0.40%	0.50%
Commercial business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 1,207,879	$ 1,207,944
Allowance for loan losses	$ 16,533	$ 13,856	12,043
Percent of total loans	16.20%	16.50%
Agricultural business, including secured by farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 369,156	$ 376,531
Allowance for loan losses	$ 2,967	$ 3,645	3,821
Percent of total loans	5.00%	5.10%
One- to four-family residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 813,077	$ 952,633
Allowance for loan losses	$ 2,238	$ 4,732	$ 5,447
Percent of total loans	10.90%	13.00%
Consumer secured by one- to four-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 493,211	$ 478,420
Percent of total loans	6.60%	6.50%
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans outstanding	$ 157,254	$ 158,470
Percent of total loans	2.10%	2.20%

LOANS RECEIVABLE AND THE ALLO67

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Purchased Credit-Impaired Loans, Changes in Accretable Yield) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Receivables [Abstract]
Outstanding contractual unpaid balance of purchased credit-impaired loans	$ 48,400	$ 83,400
Carrying balance of purchased credit-impaired loans	32,322	58,600
Accretable Yield Movement Schedule [Roll Forward]
Balance, beginning of period	10,375	0
Additions	0	13,310
Accretion to interest income	9,333	2,202
Disposals	1,018	1,238
Reclassifications from non-accretable difference	8,693	505
Balance, end of period	8,717	10,375
Non-accretable difference	$ 15,700	$ 29,500

LOANS RECEIVABLE AND THE ALLO68

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Impaired Loans With and Without Specific Reserves) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	$ 43,935	$ 41,295
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	15,815	8,637
Recorded Investment	25,671	28,360
Related Allowance	2,263	2,307
Impaired Financing Receivable, Average Recorded Investment	49,535	36,340	$ 45,440
Interest Income Recognized	1,056	1,206	1,528
Commerical real estate - owner-occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	3,786	1,465
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,778	0
Recorded Investment	1,798	1,416
Related Allowance	175	70
Impaired Financing Receivable, Average Recorded Investment	2,721	1,467	1,841
Interest Income Recognized	2	9	12
Commerical real estate - investment properties [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	9,916	8,740
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	4,015	2,503
Recorded Investment	5,854	5,846
Related Allowance	580	602
Impaired Financing Receivable, Average Recorded Investment	18,529	8,003	6,145
Interest Income Recognized	242	303	315
Multifamily real estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	508	359
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0
Recorded Investment	496	357
Related Allowance	81	71
Impaired Financing Receivable, Average Recorded Investment	513	362	795
Interest Income Recognized	21	18	45
Commercial Construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance		1,141
Impaired Financing Receivable, with No Related Allowance, Recorded Investment		1,069
Recorded Investment		0
Related Allowance		0
One-to four-family construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	1,180	1,741
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0
Recorded Investment	1,180	1,741
Related Allowance	156	161
Impaired Financing Receivable, Average Recorded Investment	1,158	1,463	2,655
Interest Income Recognized	75	114	118
Land and land development - residential [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	3,012	3,540
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	750	750
Recorded Investment	1,106	1,634
Related Allowance	219	444
Impaired Financing Receivable, Average Recorded Investment	1,948	2,406	2,872
Interest Income Recognized	85	49	89
Land and land development - commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	1,608	1,628
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	998	1,027
Recorded Investment	0	0
Related Allowance	0	0
Impaired Financing Receivable, Average Recorded Investment	1,003	931	0
Interest Income Recognized	0	0	0
Commercial business [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	3,753	2,266
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	2,294	538
Recorded Investment	1,431	1,184
Related Allowance	154	150
Impaired Financing Receivable, Average Recorded Investment	4,290	1,667	1,328
Interest Income Recognized	37	35	41
Agricultural business, including secured by farmland [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	6,438	1,309
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	5,886	544
Recorded Investment	468	697
Related Allowance	35	43
Impaired Financing Receivable, Average Recorded Investment	5,004	1,143	1,866
Interest Income Recognized	119	19	0
One- to four-family residential [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	11,439	17,897
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	90	2,206
Recorded Investment	11,085	14,418
Related Allowance	655	736
Impaired Financing Receivable, Average Recorded Investment	11,976	17,770	26,093
Interest Income Recognized	441	630	870
Consumer secured by one- to four-family [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	1,904	776
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0
Recorded Investment	1,865	716
Related Allowance	179	23
Impaired Financing Receivable, Average Recorded Investment	1,778	736	1,248
Interest Income Recognized	17	11	19
Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	391	433
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	4	0
Recorded Investment	388	351
Related Allowance	29	7
Impaired Financing Receivable, Average Recorded Investment	615	392	597
Interest Income Recognized	$ 17	$ 18	$ 19

LOANS RECEIVABLE AND THE ALLO69

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Troubled Debt Restructuring) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	$ 18,907	$ 21,777
Nonaccrual Status	1,024	2,319
Total TDRs	19,931	24,096
Financing Receivable, Modifications, Commitments to Advance Funds	127	237
Commerical real estate - owner-occupied [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	203	181
Nonaccrual Status	96	104
Total TDRs	299	285
Commerical real estate - investment properties [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	4,304	5,834
Nonaccrual Status	0	13
Total TDRs	4,304	5,847
Multifamily real estate [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	349	357
Nonaccrual Status	0	0
Total TDRs	349	357
One-to four-family construction [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	1,180	1,741
Nonaccrual Status	0	0
Total TDRs	1,180	1,741
Land and land development - residential [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	1,106	1,151
Nonaccrual Status	0	483
Total TDRs	1,106	1,634
Commercial business [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	653	624
Nonaccrual Status	0	0
Total TDRs	653	624
Agricultural business, including secured by farmland [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	3,125	545
Nonaccrual Status	79	277
Total TDRs	3,204	822
One- to four-family residential [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	7,678	11,025
Nonaccrual Status	843	1,428
Total TDRs	8,521	12,453
Consumer secured by one- to four-family [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	143	147
Nonaccrual Status	6	14
Total TDRs	149	161
Consumer Loan [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	166	172
Nonaccrual Status	0	0
Total TDRs	$ 166	$ 172

LOANS RECEIVABLE AND THE ALLO70

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Newly Restructured Loans) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)contract	Dec. 31, 2015USD ($)contract
Financing Receivable, Troubled Debt Restructurings [Line Items]
Number of Contracts | contract	2	7
Pre-Modification Outstanding Recorded Investment	$ 272	$ 2,555
Post-Modification Outstanding Recorded Investment	$ 272	$ 1,736
Commerical real estate - owner-occupied [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Number of Contracts | contract	1	0
Pre-Modification Outstanding Recorded Investment	$ 194	$ 0
Post-Modification Outstanding Recorded Investment	$ 194	$ 0
Land and land development - residential [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Number of Contracts | contract	0	2
Pre-Modification Outstanding Recorded Investment	$ 0	$ 1,302
Post-Modification Outstanding Recorded Investment	$ 0	$ 483
Agricultural business, including secured by farmland [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Number of Contracts | contract	0	3
Pre-Modification Outstanding Recorded Investment	$ 0	$ 822
Post-Modification Outstanding Recorded Investment	$ 0	$ 822
One- to four-family residential [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Number of Contracts | contract	1	2
Pre-Modification Outstanding Recorded Investment	$ 78	$ 431
Post-Modification Outstanding Recorded Investment	$ 78	$ 431

LOANS RECEIVABLE AND THE ALLO71

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Troubled Debt Restructuring Which Incurred Payment Default) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016loan	Dec. 31, 2015USD ($)loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDRs Which Incurred Payment Default, Number of Loans | loan	0	3
TDRs Which Incurred a Payment Default | $		$ 664
Agricultural Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDRs Which Incurred Payment Default, Number of Loans | loan		2
TDRs Which Incurred a Payment Default | $		$ 277
One- to four-family residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDRs Which Incurred Payment Default, Number of Loans | loan		1
TDRs Which Incurred a Payment Default | $		$ 387

LOANS RECEIVABLE AND THE ALLO72

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Risk-Rate and Non-Risk Rated Loans by Grade and Other Characteristic) (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		$ 7,451,148	$ 7,314,504
Owner-occupied Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		1,352,999	1,327,807
Investment Properties Commerical Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		1,986,336	1,765,353
Multifamily Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		248,150	472,976
Commercial Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		124,068	72,103
Multifamily construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		124,126	63,846
One-to four-family construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		375,704	278,469
Residential Land and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		170,004	126,773
Land and land development - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		29,184	33,179
Commercial business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		1,207,879	1,207,944
Agricultural Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		369,156	376,531
One- to four-family residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		813,077	952,633
Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		493,211	478,420
Consumer Borrower [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		157,254	158,470
Pass (Risk Ratings 1-5) [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	7,282,408	7,148,698
Pass (Risk Ratings 1-5) [Member] | Small Credit-Scored Business Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		225,000	150,000
Pass (Risk Ratings 1-5) [Member] | Owner-occupied Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	1,313,142	1,281,561
Pass (Risk Ratings 1-5) [Member] | Investment Properties Commerical Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	1,948,822	1,740,720
Pass (Risk Ratings 1-5) [Member] | Multifamily Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	247,258	468,467
Pass (Risk Ratings 1-5) [Member] | Commercial Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	124,068	72,103
Pass (Risk Ratings 1-5) [Member] | Multifamily construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	124,126	63,846
Pass (Risk Ratings 1-5) [Member] | One-to four-family construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	371,636	275,154
Pass (Risk Ratings 1-5) [Member] | Residential Land and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	167,764	121,536
Pass (Risk Ratings 1-5) [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	25,090	25,786
Pass (Risk Ratings 1-5) [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	1,148,585	1,167,933
Pass (Risk Ratings 1-5) [Member] | Agricultural Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	356,656	354,760
Pass (Risk Ratings 1-5) [Member] | One- to four-family residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	807,837	943,098
Pass (Risk Ratings 1-5) [Member] | Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	490,877	476,448
Pass (Risk Ratings 1-5) [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	[1]	156,547	157,286
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		77,691	77,632
Special Mention [Member] | Owner-occupied Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		14,394	19,400
Special Mention [Member] | Investment Properties Commerical Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		23,846	11,528
Special Mention [Member] | Multifamily Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	138
Special Mention [Member] | Commercial Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Special Mention [Member] | Multifamily construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Special Mention [Member] | One-to four-family construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Special Mention [Member] | Residential Land and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	76
Special Mention [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	2,310
Special Mention [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		35,036	25,286
Special Mention [Member] | Agricultural Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		3,335	17,526
Special Mention [Member] | One- to four-family residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		967	1,346
Special Mention [Member] | Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		5	0
Special Mention [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		108	22
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		91,042	88,164
Substandard [Member] | Owner-occupied Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		25,463	26,846
Substandard [Member] | Investment Properties Commerical Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		13,668	13,105
Substandard [Member] | Multifamily Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		892	4,371
Substandard [Member] | Commercial Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Substandard [Member] | Multifamily construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Substandard [Member] | One-to four-family construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		4,068	3,315
Substandard [Member] | Residential Land and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		2,240	5,161
Substandard [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		4,094	5,083
Substandard [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		24,258	14,725
Substandard [Member] | Agricultural Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		9,165	4,245
Substandard [Member] | One- to four-family residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		4,273	8,189
Substandard [Member] | Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		2,327	1,967
Substandard [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		594	1,157
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		7	10
Doubtful [Member] | Owner-occupied Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Doubtful [Member] | Investment Properties Commerical Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Doubtful [Member] | Multifamily Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Doubtful [Member] | Commercial Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Doubtful [Member] | Multifamily construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Doubtful [Member] | One-to four-family construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Doubtful [Member] | Residential Land and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Doubtful [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Doubtful [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Doubtful [Member] | Agricultural Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Doubtful [Member] | One- to four-family residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Doubtful [Member] | Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		2	5
Doubtful [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		5	5
Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | Owner-occupied Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | Investment Properties Commerical Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | Multifamily Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | Commercial Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | Multifamily construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | One-to four-family construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | Residential Land and Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | Agricultural Business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | One- to four-family residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		0	0
Loss [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable		$ 0	$ 0
[1]	(1) The Pass category includes some performing loans that are part of homogenous pools which are not individually risk-rated. This includes all consumer loans, all one- to four-family residential loans and, as of December 31, 2016 and 2015, in the commercial business category, $225.0 million and $150.0 million, respectively, of credit-scored small business loans. As loans in these homogeneous pools become non-accrual, they are individually risk-rated.

LOANS RECEIVABLE AND THE ALLO73

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Age Analysis of Company's Past Due Loans) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 28,859	$ 24,733
Carrying balance of purchased credit-impaired loans	32,322	58,600
Current	7,389,967	7,231,171
Loans receivable	7,451,148	7,314,504
Loans 90 Days or More Past Due and Accruing	2,153	952
Financing Receivable, Recorded Investment, Nonaccrual Status	20,426	14,270
Commerical real estate - owner-occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,476	5,005
Carrying balance of purchased credit-impaired loans	13,281	24,261
Current	1,335,242	1,298,541
Loans receivable	1,352,999	1,327,807
Loans 90 Days or More Past Due and Accruing	0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	3,373	1,235
Commerical real estate - investment properties [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,564	4,398
Carrying balance of purchased credit-impaired loans	10,168	16,724
Current	1,970,604	1,744,231
Loans receivable	1,986,336	1,765,353
Loans 90 Days or More Past Due and Accruing	701	0
Financing Receivable, Recorded Investment, Nonaccrual Status	4,864	2,516
Multifamily real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	147	4
Carrying balance of purchased credit-impaired loans	139	1,994
Current	247,864	470,978
Loans receivable	248,150	472,976
Loans 90 Days or More Past Due and Accruing	147	0
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Commercial Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Carrying balance of purchased credit-impaired loans	0	0
Current	124,068	72,103
Loans receivable	124,068	72,103
Loans 90 Days or More Past Due and Accruing	0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Multifamily construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	784
Carrying balance of purchased credit-impaired loans	0	0
Current	124,126	63,062
Loans receivable	124,126	63,846
Loans 90 Days or More Past Due and Accruing	0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
One-to four-family construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	2,686
Carrying balance of purchased credit-impaired loans	862	905
Current	374,842	274,878
Loans receivable	375,704	278,469
Loans 90 Days or More Past Due and Accruing	0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	0	1,233
Land and land development - residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	798	747
Carrying balance of purchased credit-impaired loans	0	77
Current	169,206	125,949
Loans receivable	170,004	126,773
Loans 90 Days or More Past Due and Accruing	0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	750	1,027
Land and land development - commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	998	96
Carrying balance of purchased credit-impaired loans	3,016	4,668
Current	25,170	28,415
Loans receivable	29,184	33,179
Loans 90 Days or More Past Due and Accruing	0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	998	0
Commercial business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,552	3,042
Carrying balance of purchased credit-impaired loans	3,821	7,302
Current	1,199,506	1,197,600
Loans receivable	1,207,879	1,207,944
Loans 90 Days or More Past Due and Accruing	0	8
Financing Receivable, Recorded Investment, Nonaccrual Status	3,074	2,159
Agricultural business, including secured by farmland [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,372	1,330
Carrying balance of purchased credit-impaired loans	684	1,529
Current	364,100	373,672
Loans receivable	369,156	376,531
Loans 90 Days or More Past Due and Accruing	0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	3,229	697
One- to four-family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,152	5,304
Carrying balance of purchased credit-impaired loans	274	1,066
Current	808,651	946,263
Loans receivable	813,077	952,633
Loans 90 Days or More Past Due and Accruing	1,233	899
Financing Receivable, Recorded Investment, Nonaccrual Status	2,263	4,700
Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,078	563
Carrying balance of purchased credit-impaired loans	18	40
Current	491,115	477,817
Loans receivable	493,211	478,420
Loans 90 Days or More Past Due and Accruing	61	4
Financing Receivable, Recorded Investment, Nonaccrual Status	1,660	565
Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,722	774
Carrying balance of purchased credit-impaired loans	59	34
Current	155,473	157,662
Loans receivable	157,254	158,470
Loans 90 Days or More Past Due and Accruing	11	41
Financing Receivable, Recorded Investment, Nonaccrual Status	215	138
30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	8,923	12,725
30 to 59 Days Past Due [Member] | Commerical real estate - owner-occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,938	3,981
30 to 59 Days Past Due [Member] | Commerical real estate - investment properties [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	117	1,763
30 to 59 Days Past Due [Member] | Multifamily real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	4
30 to 59 Days Past Due [Member] | Commercial Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
30 to 59 Days Past Due [Member] | Multifamily construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	771
30 to 59 Days Past Due [Member] | One-to four-family construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	2,466
30 to 59 Days Past Due [Member] | Land and land development - residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	48	0
30 to 59 Days Past Due [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
30 to 59 Days Past Due [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,314	1,844
30 to 59 Days Past Due [Member] | Agricultural business, including secured by farmland [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	360	323
30 to 59 Days Past Due [Member] | One- to four-family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,793	620
30 to 59 Days Past Due [Member] | Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	932	465
30 to 59 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,421	488
60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,454	2,591
60 to 89 Days Past Due [Member] | Commerical real estate - owner-occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	139
60 to 89 Days Past Due [Member] | Commerical real estate - investment properties [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	132
60 to 89 Days Past Due [Member] | Multifamily real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
60 to 89 Days Past Due [Member] | Commercial Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
60 to 89 Days Past Due [Member] | Multifamily construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	13
60 to 89 Days Past Due [Member] | One-to four-family construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	220
60 to 89 Days Past Due [Member] | Land and land development - residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
60 to 89 Days Past Due [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	96
60 to 89 Days Past Due [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	647	174
60 to 89 Days Past Due [Member] | Agricultural business, including secured by farmland [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,244	729
60 to 89 Days Past Due [Member] | One- to four-family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	249	873
60 to 89 Days Past Due [Member] | Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	160	60
60 to 89 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	154	155
90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	17,482	9,417
90 Days or More Past Due [Member] | Commerical real estate - owner-occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,538	885
90 Days or More Past Due [Member] | Commerical real estate - investment properties [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,447	2,503
90 Days or More Past Due [Member] | Multifamily real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	147	0
90 Days or More Past Due [Member] | Commercial Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
90 Days or More Past Due [Member] | Multifamily construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
90 Days or More Past Due [Member] | One-to four-family construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
90 Days or More Past Due [Member] | Land and land development - residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	750	747
90 Days or More Past Due [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	998	0
90 Days or More Past Due [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,591	1,024
90 Days or More Past Due [Member] | Agricultural business, including secured by farmland [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,768	278
90 Days or More Past Due [Member] | One- to four-family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,110	3,811
90 Days or More Past Due [Member] | Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	986	38
90 Days or More Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 147	$ 131

LOANS RECEIVABLE AND THE ALLO74

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Allowance for Credit Losses) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance				$ 78,008				$ 75,907					$ 78,008	$ 75,907
Provision for loan losses	$ 2,030	$ 2,000	$ 2,000	0	$ 0	$ 0	$ 0	0	$ 0	$ 0	$ 0	$ 0	6,030	0	$ 0
Recoveries													6,698	6,960
Charge-offs													(4,739)	(4,859)
Ending balance	85,997				78,008				75,907				85,997	78,008	75,907
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment																$ 1,420	$ 1,920
Allowance collectively evaluated for impairment																84,544	76,033
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses																	55
Allowance for loan losses	85,997			78,008	78,008			75,907	75,907				78,008	75,907	75,907	85,997	78,008
Loans individually evaluated for impairment																30,382	28,816
Loans collectively evaluated for impairment																7,388,444	7,227,088
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net																32,322	58,600
Loans receivable																7,451,148	7,314,504
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance				20,716				18,784					20,716	18,784
Provision for loan losses													441	1,177
Recoveries													582	819
Charge-offs													(746)	(64)
Ending balance	20,993				20,716				18,784				20,993	20,716	18,784
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment																428	605
Allowance collectively evaluated for impairment																20,565	20,111
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses																0	0
Allowance for loan losses	20,993			20,716	20,716			18,784	18,784				20,716	18,784	18,784	20,993	20,716
Loans individually evaluated for impairment																10,300	8,519
Loans collectively evaluated for impairment																3,305,586	3,043,656
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net																23,449	40,985
Loans receivable																3,339,335	3,093,160
Multifamily Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance				4,195				4,562					4,195	4,562
Provision for loan losses													(2,835)	(480)
Recoveries													0	113
Charge-offs													0	0
Ending balance	1,360				4,195				4,562				1,360	4,195	4,562
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment																64	71
Allowance collectively evaluated for impairment																1,296	4,124
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses																0	0
Allowance for loan losses	1,360			4,195	4,195			4,562	4,562				4,195	4,562	4,562	1,360	4,195
Loans individually evaluated for impairment																349	357
Loans collectively evaluated for impairment																247,662	470,625
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net																139	1,994
Loans receivable																248,150	472,976
Construction and Land [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance				27,131				25,545					27,131	25,545
Provision for loan losses													5,566	666
Recoveries													2,171	1,811
Charge-offs													(616)	(891)
Ending balance	34,252				27,131				25,545				34,252	27,131	25,545
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment																374	418
Allowance collectively evaluated for impairment																33,845	26,713
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses																33	0
Allowance for loan losses	34,252			27,131	27,131			25,545	25,545				27,131	25,545	25,545	34,252	27,131
Loans individually evaluated for impairment																4,034	4,669
Loans collectively evaluated for impairment																815,174	564,051
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net																3,878	5,650
Loans receivable																823,086	574,370
Commercial business [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance				13,856				12,043					13,856	12,043
Provision for loan losses													1,632	1,611
Recoveries													1,993	948
Charge-offs													(948)	(746)
Ending balance	16,533				13,856				12,043				16,533	13,856	12,043
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment																69	69
Allowance collectively evaluated for impairment																16,464	13,732
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses																0	55
Allowance for loan losses	16,533			13,856	13,856			12,043	12,043				13,856	12,043	12,043	16,533	13,856
Loans individually evaluated for impairment																2,946	2,223
Loans collectively evaluated for impairment																1,201,112	1,198,419
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net																3,821	7,302
Loans receivable																1,207,879	1,207,944
Agricultural Business [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance				3,645				3,821					3,645	3,821
Provision for loan losses													(170)	(878)
Recoveries													59	1,927
Charge-offs													(567)	(1,225)
Ending balance	2,967				3,645				3,821				2,967	3,645	3,821
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment																0	0
Allowance collectively evaluated for impairment																2,967	3,645
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses																0	0
Allowance for loan losses	2,967			3,645	3,645			3,821	3,821				3,645	3,821	3,821	2,967	3,645
Loans individually evaluated for impairment																4,766	544
Loans collectively evaluated for impairment																363,706	374,458
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net																684	1,529
Loans receivable																369,156	376,531
One- to four-family residential [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance				4,732				5,447					4,732	5,447
Provision for loan losses													(3,402)	(1,068)
Recoveries													1,283	772
Charge-offs													(375)	(419)
Ending balance	2,238				4,732				5,447				2,238	4,732	5,447
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment																480	728
Allowance collectively evaluated for impairment																1,758	4,004
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses																0	0
Allowance for loan losses	2,238			4,732	4,732			5,447	5,447				4,732	5,447	5,447	2,238	4,732
Loans individually evaluated for impairment																7,678	12,185
Loans collectively evaluated for impairment																805,125	939,382
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net																274	1,066
Loans receivable																813,077	952,633
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance				902				483					902	483
Provision for loan losses													4,079	1,363
Recoveries													610	570
Charge-offs													(1,487)	(1,514)
Ending balance	4,104				902				483				4,104	902	483
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment																5	29
Allowance collectively evaluated for impairment																4,099	873
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses																0	0
Allowance for loan losses	4,104			902	902			483	483				902	483	483	4,104	902
Loans individually evaluated for impairment																309	319
Loans collectively evaluated for impairment																650,079	636,497
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net																77	74
Loans receivable																650,465	636,890
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance				2,831				5,222					2,831	5,222
Provision for loan losses													719	(2,391)
Recoveries													0	0
Charge-offs													0	0
Ending balance	3,550				2,831				5,222				3,550	2,831	5,222
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance individually evaluated for impairment																0	0
Allowance collectively evaluated for impairment																3,550	2,831
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses																0	0
Allowance for loan losses	3,550			$ 2,831	$ 2,831			$ 5,222	$ 5,222				2,831	$ 5,222	$ 5,222	3,550	2,831
Loans individually evaluated for impairment																0	0
Loans collectively evaluated for impairment																0	0
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net																0	0
Loans receivable																0	$ 0
Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Ending balance	33												33
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Allowance for loan losses	$ 33												$ 33			$ 33

REAL ESTATE OWNED, HELD FOR S75

REAL ESTATE OWNED, HELD FOR SALE, NET (REO Rollforward) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Real Estate [Abstract]
Real Estate Acquired Through Foreclosure	$ 917,000	$ 3,400,000
Mortgage Loans in Process of Foreclosure, Amount	715,000	2,800,000
Real Estate Owned [Roll Forward]
Balance, beginning of period	11,627,000	3,352,000	$ 4,044,000
Additions from loan foreclosures	8,909,000	4,351,000	3,264,000
Additions from capitalized costs	0	298,000	30,000
Real Estate Owned, Additions from Acquisitions	400,000	8,231,000	0
Proceeds from dispositions of REO	(10,812,000)	(4,740,000)	(4,923,000)
Gain on sale of REO	1,833,000	351,000	973,000
Valuation adjustments in the period	(876,000)	(216,000)	(36,000)
Balance, ending of period	$ 11,081,000	$ 11,627,000	$ 3,352,000

PROPERTY AND EQUIPMENT, NET (De

PROPERTY AND EQUIPMENT, NET (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Land1	$ 35,463	$ 38,992
Buildings and leasehold improvements(1)	162,342	160,075
Furniture and equipment	91,706	79,018
Property and equipment, gross	289,511	278,085
Less accumulated depreciation	(123,030)	(110,481)
Property and equipment, net	$ 166,481	$ 167,604

PROPERTY AND EQUIPMENT, NET (Op

PROPERTY AND EQUIPMENT, NET (Operating Lease Commitments) (Details) $ in Millions	Dec. 31, 2016USD ($)
Property, Plant and Equipment [Abstract]
2,016	$ 14.6
2,017	12.7
2,018	10.1
2,019	8.8
2,020	7.2
Thereafter	16.1
Total	$ 69.5

PROPERTY AND EQUIPMENT, NET PRO

PROPERTY AND EQUIPMENT, NET PROPERTY AND EQUIPMENT, NET (Textual) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 13,464	$ 9,957	$ 8,064
Rental expense	$ 16,700	$ 10,200	$ 7,600

DEPOSITS (Deposit Liabilities)

DEPOSITS (Deposit Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deposit Liabilities [Line Items]
Non-interest-bearing checking	$ 3,140,451	$ 2,619,618
Interest-bearing checking	914,484	1,159,846
Regular savings accounts	1,523,391	1,284,642
Money market accounts	1,497,755	1,637,092
Total interest-bearing transaction and savings accounts	3,935,630	4,081,580
Time Deposits, $250,000 or less	884,403	1,168,495
Time Deposits, More than $250,000	160,930	185,375
Interest-bearing certificates	1,045,333	1,353,870
Total deposits	8,121,414	8,055,068
Included in total deposits:
Public fund transaction accounts	221,765	209,430
Public fund interest-bearing certificates	25,650	31,281
Total public deposits	247,415	240,711
Total brokered deposits	34,074	162,936
Related Party Deposit Liabilities	$ 7,200	$ 6,600

DEPOSITS (Maturities and Weight

DEPOSITS (Maturities and Weighted Average Interest Rates of Certificates of Deposit) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Maturities of Time Deposits [Abstract]
Maturing in one year or less	$ 765,406
Maturing after one year through two years	159,436
Maturing after two years through three years	60,932
Maturing after three years through four years	26,238
Maturing after four years through five years	29,912
Maturing after five years	3,409
Total certificates of deposit	$ 1,045,333	$ 1,353,870
Weighted Average Rate [Abstract]
Maturing in one year or less	0.45%
Maturing after one year through two years	0.76%
Maturing after two years through three years	0.88%
Maturing after three years through four years	1.19%
Maturing after four years through five years	1.06%
Maturing after five years	1.26%
Total certificates of deposits	0.56%

ADVANCES FROM FEDERAL HOME LO81

ADVANCES FROM FEDERAL HOME LOAN BANK OF DES MOINES (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Advances from Federal Home Loan Banks [Abstract]
Federal Home Loan Bank, advances, collateral pledged	$ 0
Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract]
Maturing in one year or less	54,000,000	$ 107,600,000
Maturing after one year through three years	0	25,000,000
Maturing after three years through five years	0	0
Maturing after five years	179,000	188,000
Total FHLB advances, at par	54,179,000	132,788,000
Fair value adjustment	37,000	593,000
Total FHLB advances, carried at fair value	54,216,000	133,381,000
Federal Home Loan Bank, advances, maximum outstanding at any month end	300,200,000	221,600,000
Federal Home Loan Bank, advances, average balance outstanding	$ 141,900,000	$ 45,000,000
Federal Home Loan Bank, advances, average interest rate for year	0.67%	0.69%
Subsidiary, Banner Bank [Member]
Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract]
Federal Home Loan Bank, advances, percentage of total assets to support credit line	35.00%
Federal Home Loan Bank, advances, maximum credit line	$ 3,350,000,000
Subsidiary, Islanders Bank [Member]
Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract]
Federal Home Loan Bank, advances, percentage of total assets to support credit line	35.00%
Federal Home Loan Bank, advances, maximum credit line	$ 98,100,000

OTHER BORROWINGS (Schedule of O

OTHER BORROWINGS (Schedule of Other Borrowings) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Amount:
Total year-end outstanding	$ 105,685	$ 98,325
Repurchase Agreements [Member] | Retail repurchase agreements [Member]
Amount:
Maturing in one year or less	100,685	93,325
Maturing after one year through two years	5,000	0
Maturing after two years	0	5,000
Total year-end outstanding	$ 105,685	$ 98,325
Weighted Average Rate:
Maturing in one year or less, weighted average interest rate	0.19%	0.19%
Maturing after one year through two years, weighted average interest rate	2.15%	0.00%
Maturing after two years, weighted average interest rate	0.00%	2.15%
Total year-end outstanding, weighted average interest rate	0.28%	0.29%
Other Borrowings, Activity for Year [Abstract]
Average outstanding	$ 108,427	$ 94,182
Average outstanding, weighted average interest rate	0.29%	0.22%
Maximum outstanding at any month end	$ 112,309	$ 102,474

OTHER BORROWINGS (Textuals) (De

OTHER BORROWINGS (Textuals) (Details)	Dec. 31, 2016USD ($)agreement	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Securities pledged to secure retail repurchase agreements	$ 114,949,000
Funds Borrowed Against Current Borrowing Capacity	105,685,000		$ 98,325,000
Repurchase Agreements [Member] | Retail repurchase agreements [Member]
Debt Instrument [Line Items]
Funds Borrowed Against Current Borrowing Capacity	$ 105,685,000		98,325,000
Repurchase Agreements [Member] | Retail repurchase agreements [Member] | Minimum [Member]
Debt Instrument [Line Items]
Repurchase agreements, interest rate	0.15%
Repurchase Agreements [Member] | Retail repurchase agreements [Member] | Maximum [Member]
Debt Instrument [Line Items]
Repurchase agreements, interest rate	0.40%
Repurchase Agreements [Member] | Repurchase Agreement, Wholesale [Member]
Debt Instrument [Line Items]
Repurchase agreements, interest rate	2.15%
Number of repurchase agreements | agreement	1
Federal Reserve Bank Advances [Member] | Federal Reserve Bank of San Francisco [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 1,020,000,000
Funds Borrowed Against Current Borrowing Capacity	0
Subsidiary, Banner Bank [Member] | Federal Funds Purchased [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	60,000,000
Line of credit, current	0	$ 0
Balance outstanding	0		$ 0
Subsidiary, Islanders Bank [Member] | Federal Funds Purchased [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	5,000,000
Line of credit, current	$ 0	$ 0

JUNIOR SUBORDINATED DEBENTURE84

JUNIOR SUBORDINATED DEBENTURES AND MANDATORILY REDEEMABLE TRUST PREFERRED SECURITIES (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)subsidiary	Dec. 31, 2015USD ($)
Schedule of Trust Preferred Securities [Line Items]
Number of wholly-owned Grantor Trusts | subsidiary	9
Grantor trusts amount of tier one risk based capital	$ 1,125,267	$ 1,057,597
Debentures Subject to Mandatory Redemption [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	140,212
Fair value adjustment	(45,012)
Total TPS liability at fair value	$ 95,200
Current Interest Rate	3.03%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trusts [Member]
Schedule of Trust Preferred Securities [Line Items]
Grantor trusts amount of tier one risk based capital	$ 136,000
Grantor trusts percentage of tier one risk based capital	11.20%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust II [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 15,464
Current Interest Rate	4.23%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	3.35%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust III [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 15,465
Current Interest Rate	3.78%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	2.90%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust IV [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 15,465
Current Interest Rate	3.73%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	2.85%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust V [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 25,774
Current Interest Rate	2.49%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	1.57%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust VI [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 25,774
Current Interest Rate	2.46%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	1.62%
Debentures Subject to Mandatory Redemption [Member] | Banner Capital Trust VII [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 25,774
Current Interest Rate	2.23%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	1.38%
Debentures Subject to Mandatory Redemption [Member] | Siuslaw Statutory Trust One [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 8,248
Current Interest Rate	3.69%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	2.70%
Debentures Subject to Mandatory Redemption [Member] | Greater Sacramento Bancorp Statutory Trust one [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 4,124
Current Interest Rate	4.23%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	3.35%
Debentures Subject to Mandatory Redemption [Member] | Greater Sacramento Bancorp Statutory Trust Two [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 4,124
Current Interest Rate	2.64%
Interest Rate Spread, Description	Three-month LIBOR
Interest Rate Spread	1.68%
Aggregate Liquidation Amount of Trust Preferred Securities [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 136,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust II [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	15,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust III [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	15,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust IV [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	15,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust V [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	25,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust VI [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	25,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Banner Capital Trust VII [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	25,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Siuslaw Statutory Trust One [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	8,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Greater Sacramento Bancorp Statutory Trust one [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	4,000
Aggregate Liquidation Amount of Trust Preferred Securities [Member] | Greater Sacramento Bancorp Statutory Trust Two [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	4,000
Aggregate Liquidation Amount of Common Capital Securities [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	4,212
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust II [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	464
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust III [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	465
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust IV [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	465
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust V [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	774
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust VI [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	774
Aggregate Liquidation Amount of Common Capital Securities [Member] | Banner Capital Trust VII [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	774
Aggregate Liquidation Amount of Common Capital Securities [Member] | Siuslaw Statutory Trust One [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	248
Aggregate Liquidation Amount of Common Capital Securities [Member] | Greater Sacramento Bancorp Statutory Trust one [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	124
Aggregate Liquidation Amount of Common Capital Securities [Member] | Greater Sacramento Bancorp Statutory Trust Two [Member]
Schedule of Trust Preferred Securities [Line Items]
Total TPS liability at par	$ 124

INCOME TAXES (Components of Inc

INCOME TAXES (Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current Federal, State and Local, Tax Expense (Benefit) [Abstract]
Current Federal Tax Expense (Benefit)													$ 29,787	$ 24,683	$ 23,411
Current State and Local Tax Expense (Benefit)													2,477	1,399	1,444
Current													32,264	26,082	24,855
Deferred Federal, State and Local, Tax Expense (Benefit) [Abstract]
Deferred Federal Income Tax Expense (Benefit)													9,908	(3,310)	2,764
Deferred State and Local Income Tax Expense (Benefit)													2,083	(23)	(567)
Deferred													11,991	(3,333)	2,197
Provision for (benefit from) income taxes	$ 11,943	$ 12,277	$ 10,841	$ 9,194	$ 3,308	$ 6,642	$ 6,615	$ 6,184	$ 5,831	$ 7,284	$ 8,696	$ 5,241	$ 44,255	$ 22,749	$ 27,052

INCOME TAXES (Effective Income

INCOME TAXES (Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Federal income tax statutory rate	35.00%	35.00%	35.00%
Increase (decrease) in tax rate due to:
Tax-exempt interest	(2.60%)	(3.90%)	(2.60%)
Investment in life insurance	(1.20%)	(1.30%)	(0.80%)
State income taxes, net of federal tax offset	2.20%	1.10%	1.10%
Tax credits	(0.80%)	(1.60%)	(0.80%)
Merger and acquisition costs	0.00%	1.90%	0.70%
Other	1.50%	2.30%	0.70%
Effective income tax rate	34.10%	33.50%	33.30%

INCOME TAXES (Schedule of Net D

INCOME TAXES (Schedule of Net Deferred Tax Asset ) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Loan loss and REO	$ 36,719	$ 33,312
Deferred compensation	23,189	19,253
Net operating loss carryforward	82,714	91,893
Federal and state tax credits	7,711	7,877
State net operating losses	7,396	8,692
Deferred Tax Asset, Loan Discount	9,696	13,412
Other	6,217	5,620
Total deferred tax assets	173,642	180,059
Deferred tax liabilities:
Depreciation	(2,218)	(1,103)
Deferred loan fees, servicing rights and loan origination costs	13,291	9,884
Intangibles	(11,178)	(13,320)
Financial instruments accounted for under fair value accounting	(16,186)	(17,112)
Unrealized (gain) loss on securities - available-for-sale	(880)	(1,475)
Total deferred tax liabilities	(43,753)	(42,894)
Deferred income tax asset	129,889	137,165
Valuation allowance	2,195	2,195
Deferred tax asset, net	$ 127,694	$ 134,970

INCOME TAXES (Textuals) (Detail

INCOME TAXES (Textuals) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Operating loss carryforward, amount expected to be utilized on an annual basis	$ 6,900
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	236,300	$ 262,500
Operating loss carryforward, amount expected to be utilized on an annual basis	21,500
Tax basis bad debt reserves for which no income tax liability has been booked	5,400
Unrecognized deferred tax liability related to bad debt reserves	1,900
Domestic Tax Authority [Member] | General Business Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Federal and state tax credit carryforwards	3,300	3,300
Domestic Tax Authority [Member] | Alternative Minimum Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Federal and state tax credit carryforwards	4,200	4,200
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	145,800	$ 167,600
Operating loss carryforwards, valuation allowance	2,200
Operating loss carryforward, amount expected to be utilized on an annual basis, valuation allowance	2,200
State and Local Jurisdiction [Member] | Alternative Minimum Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Federal and state tax credit carryforwards	$ 193

INCOME TAXES Affordable Housing

INCOME TAXES Affordable Housing Tax Credit Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Amortization Method Qualified Affordable Housing Project Investments	$ 4,654	$ 5,326
Qualified Affordable Housing Project Investments, Commitment	665	1,398
Affordable Housing Tax Credits and Other Tax Benefits, Amount	1,136	1,273
Amortization Method Qualified Affordable Housing Project Investments, Amortization	$ 672	$ 1,000

EMPLOYEE BENEFIT PLANS (Details

EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Defined contribution plan expense	$ 4,600	$ 2,800	$ 1,400
Defined contribution plan, employer matching contribution percent	4.00%
Deferred compensation liability	$ 40,074	40,474
Carrying value of shares held in trust for stock related compensation plans	7,283	6,928
Cash surrender value of bank-owned life insurance policies	158,900	156,900
Supplemental Retirement and Salary Contribution Plans [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred compensation plans expense	2,700	1,300	$ 1,200
Deferred compensation liability	38,300	39,000
Deferred Compensation Plans and Rabbi Trusts [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred compensation liability	9,000	8,400
Carrying value of shares held in trust for stock related compensation plans	7,300	6,900
Shares held in Treasury for future payment	$ 7,300	$ 6,900

STOCK-BASED COMPENSATION PLAN91

STOCK-BASED COMPENSATION PLANS (Financial Data Pertaining to Outstanding Stock Options) (Details) - Stock Option Plans [Member] - Stock Options [Member] - $216.16 [Member]	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price	$ 216.16
Weighted Average Exercise Price of Option Shares Granted	$ 216.16
Number of Option Shares Granted | shares	5,000
Weighted Average Option Shares Vested and Exercisable | shares	5,000
Weighted Average Exercise Price of Option Shares Exercisable	$ 216.16
Remaining Contractual Life	7 months

STOCK-BASED COMPENSATION PLAN92

STOCK-BASED COMPENSATION PLANS (Restricted Stock and Restricted Stock Units Activity) (Details) - Restricted Stock and Restricted Stock Units [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Unvested Shares: [Roll Forward]
Unvested, Beginning Balance	231,562	195,106	164,492
Granted	177,775	155,183	90,181
Vested	(104,297)	(109,416)	(56,307)
Forfeited	(14,321)	(9,311)	(3,260)
Unvested, Ending Balance	290,719	231,562	195,106
Weighted Average Grant-Date Fair Value (in dollars per share):
Unvested, Beginning Balance	$ 42.33	$ 32.83	$ 26.94
Granted	41.74	45.59	40.07
Vested	41.47	30.28	24.81
Forfeited	42.54	39.07	31
Unvested, Ending Balance	$ 42.26	$ 42.33	$ 32.83

STOCK-BASED COMPENSATION PLAN93

STOCK-BASED COMPENSATION PLANS (Textuals) (Details) - USD ($)	12 Months Ended			32 Months Ended	50 Months Ended	56 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2016
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 4,500,000	$ 3,500,000	$ 2,700,000
Unrecognized compensation expense	$ 6,800,000			$ 6,800,000		$ 6,800,000
Unrecognized compensation expense, period for recognition	36 months
Stock Option Plans [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	68,571			68,571		68,571
Stock-based compensation expense	$ 0	$ 0
Stock Options Exercised	0
Exercise price percentage of fair value of stock	100.00%
Share-based Compensation Arrangement by Share-based Payment Award, Annual Vesting Percentage	20.00%
Award termination period	10 years
Award forfeiture period	90 days
Stock options granted in period	0	0
2012 Restricted Stock and Incentive Bonus Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	300,000			300,000		300,000
2012 Restricted Stock and Incentive Bonus Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Shares granted in period						297,157
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period					207,338
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	89,819			89,819		89,819
Award termination period	10 years
2014 Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	900,000			900,000		900,000
2014 Omnibus Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted in period				239,088
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period				46,011
2014 Omnibus Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted in period				26,154
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period				18,331

PREFERRED STOCK AND RELATED W94

PREFERRED STOCK AND RELATED WARRANT (Details) - U.S. Treasury Capital Purchase Program [Member] $ / shares in Units, $ in Millions	Nov. 21, 2008USD ($)$ / sharesshares
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares issued | shares	124,000
Preferred stock, liquidation value per share	$ 1,000
Preferred stock aggregate liquidation preference | $	$ 124
Common Stock [Member] | Warrant [Member]
Class of Stock [Line Items]
U.S. Treasury warrants, term (in years)	10 years
Warrant, option to purchase common stock (in shares) | shares	243,998
Common stock, par value per share	$ 0.01
U.S. Treasury warrants, exercise price per share	$ 76.23
U.S. Treasury warrants, aggregate exercise price | $	$ 18.6

REGULATORY CAPITAL REQUIREMEN95

REGULATORY CAPITAL REQUIREMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Total capital to risk-weighted assets:
Actual	$ 1,214,913	$ 1,139,554
Actual, Ratio	13.40%	13.63%
Minimum for Capital Adequacy Purposes	$ 725,566	$ 668,941
Minimum for Capital Adequacy Purposes, Ratio	8.00%	8.00%
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions	$ 906,957	$ 836,530
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%	10.00%
Tier 1 capital to risk-weighted assets:
Actual	$ 1,125,267	$ 1,057,597
Actual, Ratio	12.41%	12.65%
Minimum for Capital Adequacy Purposes	$ 544,174	$ 501,706
Minimum for Capital Adequacy Purposes, Ratio	6.00%	6.00%
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions	$ 544,174	$ 501,918
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	6.00%	6.00%
Tier 1 common equity to risk-weighted assets:
Actual	$ 1,014,994	$ 1,013,971
Actual, Ratio	11.19%	12.13%
Minimum for Capital Adequacy Purposes	$ 408,131	$ 376,279
Minimum for Capital Adequacy Purposes, Ratio	4.50%	4.50%
Tier 1 leverage capital to average assets:
Actual	$ 1,125,267	$ 1,057,597
Actual, Ratio	11.83%	11.06%
Minimum for Capital Adequacy Purposes	$ 380,519	$ 382,617
Minimum for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Banner Bank [Member]
Total capital to risk-weighted assets:
Actual	$ 1,043,837	$ 1,030,601
Actual, Ratio	11.76%	12.61%
Minimum for Capital Adequacy Purposes	$ 709,882	$ 653,606
Minimum for Capital Adequacy Purposes, Ratio	8.00%	8.00%
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions	$ 887,352	$ 817,008
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%	10.00%
Tier 1 capital to risk-weighted assets:
Actual	$ 956,298	$ 950,865
Actual, Ratio	10.78%	11.64%
Minimum for Capital Adequacy Purposes	$ 532,411	$ 490,205
Minimum for Capital Adequacy Purposes, Ratio	6.00%	6.00%
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions	$ 709,882	$ 653,606
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	8.00%	8.00%
Tier 1 common equity to risk-weighted assets:
Actual	$ 956,298	$ 950,865
Actual, Ratio	10.78%	11.64%
Minimum for Capital Adequacy Purposes	$ 399,308	$ 367,653
Minimum for Capital Adequacy Purposes, Ratio	4.50%	4.50%
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions	$ 576,779	$ 531,055
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	6.50%	6.50%
Tier 1 leverage capital to average assets:
Actual	$ 956,298	$ 950,865
Actual, Ratio	10.34%	10.23%
Minimum for Capital Adequacy Purposes	$ 369,936	$ 371,807
Minimum for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions	$ 462,420	$ 464,759
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%	5.00%
Islanders Bank
Total capital to risk-weighted assets:
Actual	$ 35,207	$ 38,448
Actual, Ratio	18.43%	20.31%
Minimum for Capital Adequacy Purposes	$ 15,281	$ 15,146
Minimum for Capital Adequacy Purposes, Ratio	8.00%	8.00%
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions	$ 19,101	$ 18,932
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%	10.00%
Tier 1 capital to risk-weighted assets:
Actual	$ 33,099	$ 36,227
Actual, Ratio	17.33%	19.14%
Minimum for Capital Adequacy Purposes	$ 11,461	$ 11,359
Minimum for Capital Adequacy Purposes, Ratio	6.00%	6.00%
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions	$ 15,281	$ 15,146
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	8.00%	8.00%
Tier 1 common equity to risk-weighted assets:
Actual	$ 33,099	$ 36,227
Actual, Ratio	17.33%	19.14%
Minimum for Capital Adequacy Purposes	$ 8,598	$ 8,520
Minimum for Capital Adequacy Purposes, Ratio	4.50%	4.50%
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions	$ 12,416	$ 12,306
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	6.50%	6.50%
Tier 1 leverage capital to average assets:
Actual	$ 33,099	$ 36,227
Actual, Ratio	12.72%	13.38%
Minimum for Capital Adequacy Purposes	$ 10,405	$ 10,826
Minimum for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions	$ 13,006	$ 13,533
Minimum to be Categorized as Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%	5.00%

GOODWILL, OTHER INTANGIBLE AS96

GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Details)	12 Months Ended
	Dec. 31, 2016
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	3 years
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	10 years

GOODWILL, OTHER INTANGIBLE AS97

GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Finite-Lived Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015		Dec. 31, 2014
Goodwill [Line Items]
Goodwill, beginning of period	$ 247,738	$ 0		$ 0
Intangible Assets, Net (Including Goodwill), beginning of period	285,210	2,831		2,449
Goodwill, Acquired During Period		247,738		0
Acquired Intangible Assets (Including Goodwill)		285,909		2,372
Amortization	(7,310)	(3,230)		(1,990)
Goodwill, Other Changes	(3,155)
Finite-Lived Intangible Assets, Other Changes	0	(300)	[1]
Intangible Assets (including Goodwill), Other Changes	(3,155)	(300)	[1]
Goodwill, end of period	244,583	247,738		0
Balance, end of period	29,701
Intangible Assets, Net (Including Goodwill), end of period	274,745	285,210		2,831
Core Deposit Intangibles [Member]
Goodwill [Line Items]
Balance, beginning of period	36,762	2,831		2,449
Additions through acquisition		37,395		2,372
Amortization	(7,061)	(3,164)		(1,990)
Balance, end of period	29,701	36,762		2,831
Other Intangible Assets [Member]
Goodwill [Line Items]
Balance, beginning of period	710	0
Additions through acquisition		776
Amortization	(249)	(66)
Balance, end of period	$ 461	$ 710		$ 0
[1]	Acquired CDI from Starbuck was adjusted for a branch that was subsequently sold.

GOODWILL, OTHER INTANGIBLE AS98

GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Estimated Annual Amortization Expense) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Year Ended December 31, 2017	$ 6,332
Year Ended December 31, 2018	5,609
Year Ended December 31, 2019	4,889
Year Ended December 31, 2020	4,169
Thereafter	8,702
Net carrying amount	29,701
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Net carrying amount	$ 29,701	$ 36,762	$ 2,831	$ 2,449

GOODWILL, OTHER INTANGIBLE AS99

GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Mortgage Servicing Rights) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Servicing Asset at Amortized Value, Balance [Roll Forward]
Servicing Asset at Amortized Cost, Additions, Acquisitions		$ 0		$ 2,172		$ 0
Serviced Loans
Servicing Assets at Amortized Value [Line Items]
Loans serviced for others		2,050,000		1,860,000
Mortgage Servicing Rights
Servicing Assets at Amortized Value [Line Items]
Custodial accounts		10,300		8,700
Servicing Asset at Amortized Value, Balance [Roll Forward]
Balance, beginning of the year		13,295	[1]	9,030	[1]	8,086
Amounts capitalized		5,965		5,313		3,023
Amortization	[2]	(4,011)		(3,220)		(2,079)
Valuation adjustments in the period		0
Balance, end of the year	[1]	15,249		13,295		$ 9,030
Valuation Allowance		$ 0		$ 0
[1]	no valuation allowance
[2]	Amortization of mortgage servicing rights is recorded as a reduction of loan servicing income and any unamortized balance is fully written off if the loan repays in full.

FAIR VALUE OF FINANCIAL INST100

FAIR VALUE OF FINANCIAL INSTRUMENTS (Assets and Liabilities Measured at Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Fair Value	$ 24,568	$ 34,134
Securities—available-for-sale	800,917	1,138,573
Held-to-maturity Securities, Fair Value	270,528	226,627
Loans receivable held for sale	9,600	0
Advances from FHLB at fair value	54,216	133,381
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	247,719	261,917
Trading Securities, Fair Value	24,568	34,134
Securities—available-for-sale	800,917	1,138,573
Held-to-maturity Securities, Fair Value	267,873	220,666
Loans receivable held for sale	246,353	44,712
Loans receivable	7,451,148	7,314,504
FHLB stock	12,506	16,057
Bank-owned life insurance	158,936	156,865
MSRs	15,249	13,295
Deposits, Demand NOW and Money Market Accounts, Fair Value Disclosure	5,552,690	5,416,556
Deposits, Savings, Fair Value Disclosure	1,523,391	1,284,642
Deposits, Certificates of Deposit, Fair Value Disclosure	1,045,333	1,353,870
Advances from FHLB at fair value	54,216	133,381
Junior subordinated debentures net of unamortized deferred issuance costs at fair value	95,200	92,480
Other borrowings	105,685	98,325
Reported Value Measurement [Member] | Interest Rate Forward Sales Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	482	471
Derivative liabilities	289	50
Reported Value Measurement [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	8,330	11,984
Derivative liabilities	8,330	11,984
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	247,719	261,917
Trading Securities, Fair Value	24,568	34,134
Securities—available-for-sale	800,917	1,138,573
Held-to-maturity Securities, Fair Value	270,528	226,627
Loans receivable held for sale	246,815	45,600
Loans receivable	7,337,608	7,084,631
FHLB stock	12,506	16,057
Bank-owned life insurance	158,936	156,865
MSRs	16,740	17,370
Deposits, Demand NOW and Money Market Accounts, Fair Value Disclosure	5,552,690	5,416,556
Deposits, Savings, Fair Value Disclosure	1,523,391	1,284,642
Deposits, Certificates of Deposit, Fair Value Disclosure	1,028,866	1,332,825
Advances from FHLB at fair value	54,216	133,381
Junior subordinated debentures net of unamortized deferred issuance costs at fair value	95,200	92,480
Other borrowings	105,685	98,325
Estimate of Fair Value Measurement [Member] | Interest Rate Forward Sales Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	482	471
Derivative liabilities	289	50
Estimate of Fair Value Measurement [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	8,330	11,984
Derivative liabilities	$ 8,330	$ 11,984

FAIR VALUE OF FINANCIAL INST101

FAIR VALUE OF FINANCIAL INSTRUMENTS (Fair Value By Balance Sheet Location) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets:
Trading Securities, Fair Value	$ 24,568	$ 34,134
Securities—available-for-sale	800,917	1,138,573
Loans Held-for-sale, Fair Value	9,600	0
Liabilities:
Advances from FHLB at fair value	54,216	133,381
Fair Value, Measurements, Recurring [Member]
Assets:
Trading Securities, Fair Value	24,568	34,134
Securities—available-for-sale	800,917	1,138,573
Assets, Fair Value Disclosure	843,897	1,185,162
Liabilities:
Advances from FHLB at fair value	54,216	133,381
Junior subordinated debentures at fair value	95,200	92,480
Financial and Nonfinancial Liabilities, Fair Value Disclosure	158,035	237,895
Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member]
Assets:
Derivatives	482	471
Liabilities:
Derivatives	289	50
Fair Value, Measurements, Recurring [Member] | Interest Rate Swap [Member]
Assets:
Derivatives	8,330	11,984
Liabilities:
Derivatives	8,330	11,984
Fair Value, Measurements, Recurring [Member] | U.S. Government and agency obligations
Assets:
Trading Securities, Fair Value	1,326	1,368
Securities—available-for-sale	56,978	30,231
Fair Value, Measurements, Recurring [Member] | Municipal bonds
Assets:
Trading Securities, Fair Value	335	341
Securities—available-for-sale	109,853	143,319
Fair Value, Measurements, Recurring [Member] | Corporate bonds
Assets:
Securities—available-for-sale	10,283	15,981
Fair Value, Measurements, Recurring [Member] | TPS and TRUP CDOs [Member]
Assets:
Trading Securities, Fair Value	21,143	18,699
Fair Value, Measurements, Recurring [Member] | Mortgage Backed Securities, Other [Member]
Assets:
Trading Securities, Fair Value	1,641	13,663
Securities—available-for-sale	594,712	918,259
Fair Value, Measurements, Recurring [Member] | Equity securities
Assets:
Trading Securities, Fair Value	123	63
Securities—available-for-sale	98	98
Fair Value, Measurements, Recurring [Member] | Asset-backed securities
Assets:
Securities—available-for-sale	28,993	30,685
Fair Value, Measurements, Recurring [Member] | Loans [Member]
Assets:
Loans Held-for-sale, Fair Value	9,600
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets:
Trading Securities, Fair Value	0	0
Securities—available-for-sale	0	0
Assets, Fair Value Disclosure	0	0
Liabilities:
Advances from FHLB at fair value	0	0
Junior subordinated debentures at fair value	0	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Interest Rate Contract [Member]
Assets:
Derivatives	0	0
Liabilities:
Derivatives	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Interest Rate Swap [Member]
Assets:
Derivatives	0	0
Liabilities:
Derivatives	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | U.S. Government and agency obligations
Assets:
Trading Securities, Fair Value	0	0
Securities—available-for-sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Municipal bonds
Assets:
Trading Securities, Fair Value	0	0
Securities—available-for-sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Corporate bonds
Assets:
Securities—available-for-sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | TPS and TRUP CDOs [Member]
Assets:
Trading Securities, Fair Value	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mortgage Backed Securities, Other [Member]
Assets:
Trading Securities, Fair Value	0	0
Securities—available-for-sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Equity securities
Assets:
Trading Securities, Fair Value	0	0
Securities—available-for-sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Asset-backed securities
Assets:
Securities—available-for-sale	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Loans [Member]
Assets:
Loans Held-for-sale, Fair Value	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets:
Trading Securities, Fair Value	3,425	15,435
Securities—available-for-sale	800,917	1,138,573
Assets, Fair Value Disclosure	822,754	1,166,463
Liabilities:
Advances from FHLB at fair value	54,216	133,381
Junior subordinated debentures at fair value	0	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	62,835	145,415
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Interest Rate Contract [Member]
Assets:
Derivatives	482	471
Liabilities:
Derivatives	289	50
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Interest Rate Swap [Member]
Assets:
Derivatives	8,330	11,984
Liabilities:
Derivatives	8,330	11,984
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | U.S. Government and agency obligations
Assets:
Trading Securities, Fair Value	1,326	1,368
Securities—available-for-sale	56,978	30,231
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Municipal bonds
Assets:
Trading Securities, Fair Value	335	341
Securities—available-for-sale	109,853	143,319
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Corporate bonds
Assets:
Securities—available-for-sale	10,283	15,981
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | TPS and TRUP CDOs [Member]
Assets:
Trading Securities, Fair Value	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Mortgage Backed Securities, Other [Member]
Assets:
Trading Securities, Fair Value	1,641	13,663
Securities—available-for-sale	594,712	918,259
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Equity securities
Assets:
Trading Securities, Fair Value	123	63
Securities—available-for-sale	98	98
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Asset-backed securities
Assets:
Securities—available-for-sale	28,993	30,685
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Loans [Member]
Assets:
Loans Held-for-sale, Fair Value	9,600
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets:
Trading Securities, Fair Value	21,143	18,699
Securities—available-for-sale	0	0
Assets, Fair Value Disclosure	21,143	18,699
Liabilities:
Advances from FHLB at fair value	0	0
Junior subordinated debentures at fair value	95,200	92,480
Financial and Nonfinancial Liabilities, Fair Value Disclosure	95,200	92,480
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Interest Rate Contract [Member]
Assets:
Derivatives	0	0
Liabilities:
Derivatives	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Interest Rate Swap [Member]
Assets:
Derivatives	0	0
Liabilities:
Derivatives	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | U.S. Government and agency obligations
Assets:
Trading Securities, Fair Value	0	0
Securities—available-for-sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Municipal bonds
Assets:
Trading Securities, Fair Value	0	0
Securities—available-for-sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Corporate bonds
Assets:
Securities—available-for-sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | TPS and TRUP CDOs [Member]
Assets:
Trading Securities, Fair Value	21,143	18,699
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Mortgage Backed Securities, Other [Member]
Assets:
Trading Securities, Fair Value	0	0
Securities—available-for-sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Equity securities
Assets:
Trading Securities, Fair Value	0	0
Securities—available-for-sale	0	$ 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Asset-backed securities
Assets:
Securities—available-for-sale	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Loans [Member]
Assets:
Loans Held-for-sale, Fair Value	$ 0

FAIR VALUE OF FINANCIAL INST102

FAIR VALUE OF FINANCIAL INSTRUMENTS (Asset Inputs) (Details) - Weighted Average [Member] - Level 3 [Member] - Income Approach Valuation Technique [Member]	12 Months Ended
	Dec. 31, 2016
TPS Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	6.00%
Junior Subordinated Debt [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	6.00%

FAIR VALUE OF FINANCIAL INST103

FAIR VALUE OF FINANCIAL INSTRUMENTS (Unobservable Inputs Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Borrowings - Junior Subordinated Debentures [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 92,480	$ 92,480	$ 78,001
Liabilities (gains) losses		2,720	2,714
Purchases, issuances and settlements		0	11,765
Paydowns and maturities	0		0
Transfers in and/or out of Level 3	0
Ending balance		95,200	92,480
TPS and TRUP CDOs [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	18,699	18,699	19,119
Assets gains (losses)		719	537
Purchases, issuances and settlements		1,725	5,697
Paydowns and maturities	0		(6,654)
Transfers in and/or out of Level 3	$ 0
Ending balance		$ 21,143	$ 18,699

FAIR VALUE OF FINANCIAL INST104

FAIR VALUE OF FINANCIAL INSTRUMENTS (Assets Measured on Nonrecurring Basis) (Details) - Nonrecurring [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		$ 2,372
REO	$ 11,081	11,627
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		0
REO	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		0
REO	0	0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	(853)	(341)
Impaired loans		2,372
REO	11,081	11,627
Impaired Loans [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	(182)	(110)
Real Estate [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	$ (671)	$ (231)

BANNER CORPORATION (PARENT C105

BANNER CORPORATION (PARENT COMPANY ONLY) (Statements of Financial Position) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Oct. 01, 2015	Dec. 31, 2014	Dec. 31, 2013
ASSETS
Other assets	$ 59,466	$ 57,840
Total assets	9,793,668	9,796,298	$ 9,900,000
LIABILITIES AND SHAREHOLDERS’ EQUITY
Junior subordinated debentures at fair value	95,200	92,480
Shareholders’ equity	1,305,710	1,300,059		$ 582,888	$ 538,331
Total liabilities and stockholders' equity	9,793,668	9,796,298
Banner Corporation
ASSETS
Cash	86,268	58,232
Investment in trust equities	4,212	4,212
Investment in subsidiaries	1,307,475	1,319,348
Other assets	13,784	21,134
Total assets	1,411,739	1,402,926
LIABILITIES AND SHAREHOLDERS’ EQUITY
Miscellaneous liabilities	8,990	7,846
Deferred tax liability	1,839	2,541
Junior subordinated debentures at fair value	95,200	92,480
Shareholders’ equity	1,305,710	1,300,059
Total liabilities and stockholders' equity	$ 1,411,739	$ 1,402,926

BANNER CORPORATION (PARENT C106

BANNER CORPORATION (PARENT COMPANY ONLY) (Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
INTEREST INCOME:
Interest-bearing deposits	$ 97,171	$ 93,708	$ 93,148	$ 91,043	$ 92,099	$ 52,188	$ 51,457	$ 46,536	$ 46,661	$ 47,064	$ 43,808	$ 42,339	$ 375,069	$ 242,279	$ 179,872
OTHER INCOME (EXPENSE):
Other income													6,001	2,821	1,885
Other expenses													(30,131)	(17,565)	(13,619)
Income before provision for income taxes	34,747	36,128	31,798	26,968	10,201	19,589	19,864	18,318	17,544	22,105	25,683	15,790	129,640	67,971	81,122
PROVISION FOR INCOME TAXES	11,943	12,277	10,841	9,194	3,308	6,642	6,615	6,184	5,831	7,284	8,696	5,241	44,255	22,749	27,052
NET INCOME	$ 22,804	$ 23,851	$ 20,957	$ 17,774	$ 6,893	$ 12,947	$ 13,249	$ 12,134	$ 11,713	$ 14,821	$ 16,987	$ 10,549	85,385	45,222	54,070
Banner Corporation
INTEREST INCOME:
Interest-bearing deposits													127	122	96
OTHER INCOME (EXPENSE):
Dividend income from subsidiaries													50,971	170,260	26,027
Equity in undistributed (distributions in excess of) income of subsidiaries													40,852	(116,120)	33,612
Other income													60	69	67
Net change in valuation of financial instruments carried at fair value													(2,720)	(2,714)	(4,073)
Interest on other borrowings													(4,040)	(3,247)	(2,914)
Other expenses													(3,450)	(7,175)	(2,519)
Income before provision for income taxes													81,800	41,195	50,296
PROVISION FOR INCOME TAXES													(3,585)	(4,027)	(3,774)
NET INCOME													$ 85,385	$ 45,222	$ 54,070

BANNER CORPORATION (PARENT C107

BANNER CORPORATION (PARENT COMPANY ONLY) (Statements of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES:
Net income	$ 22,804	$ 23,851	$ 20,957	$ 17,774	$ 6,893	$ 12,947	$ 13,249	$ 12,134	$ 11,713	$ 14,821	$ 16,987	$ 10,549	$ 85,385	$ 45,222	$ 54,070
Adjustments to reconcile net income to net cash provided from operating activities:
Decrease in deferred taxes													7,883	(3,906)	2,966
Net change in valuation of financial instruments carried at fair value													2,620	813	(1,374)
Decrease (increase) in other assets													3,759	(7,319)	(2,310)
Increase in other liabilities													(6,664)	4,090	3,370
Net cash (used by) provided from operating activities													(76,688)	15,369	98,066
INVESTING ACTIVITIES:
Net cash provided from (used by) investing activities													146,447	15,059	(164,067)
FINANCING ACTIVITIES:
Issuance of stock for shareholder reinvestment program													0	34	127
Cash dividends paid													(28,282)	(17,170)	(13,462)
Net cash (used by) provided from financing activities													(83,957)	105,417	54,724
NET CHANGE IN CASH AND CASH EQUIVALENTS													(14,198)	135,845	(11,277)
CASH AND DUE FROM BANKS, BEGINNING OF YEAR				117,657									117,657
CASH AND DUE FROM BANKS, END OF YEAR	177,083				117,657								177,083	117,657
Banner Corporation
OPERATING ACTIVITIES:
Net income													85,385	45,222	54,070
Adjustments to reconcile net income to net cash provided from operating activities:
Distributions in excess of (equity in undistributed) income of subsidiaries													(40,852)	116,120	(33,612)
Decrease in deferred taxes													(702)	(1,398)	(1,444)
Net change in valuation of financial instruments carried at fair value													2,720	2,714	4,073
Decrease (increase) in other assets													7,332	(10,655)	(3,822)
Increase in other liabilities													3,233	3,919	222
Net cash (used by) provided from operating activities													57,116	155,922	19,487
INVESTING ACTIVITIES:
Funds transferred to deferred compensation trust													(26)	(26)	(26)
Cash Dividends Paid to Parent Company by Consolidated Subsidiaries													50,000	0	0
Acquisitions													0	132,652	0
Net cash provided from (used by) investing activities													49,974	(132,678)	(26)
FINANCING ACTIVITIES:
Issuance of stock for shareholder reinvestment program													0	34	127
Payments for Repurchase of Preferred Stock and Preference Stock													50,772	0	0
Cash dividends paid													(28,282)	(17,170)	(13,462)
Net cash (used by) provided from financing activities													(79,054)	(17,136)	(13,335)
NET CHANGE IN CASH AND CASH EQUIVALENTS													28,036	6,108	6,126
CASH AND DUE FROM BANKS, BEGINNING OF YEAR				$ 58,232				$ 52,124				$ 45,998	58,232	52,124	45,998
CASH AND DUE FROM BANKS, END OF YEAR	$ 86,268				$ 58,232				$ 52,124				$ 86,268	$ 58,232	$ 52,124

STOCK REPURCHASES (Details)

STOCK REPURCHASES (Details) - Common Stock [Member] - shares	12 Months Ended
	Dec. 31, 2016	Apr. 04, 2016
Stock repurchases
Stock surrendered during period, shares	25,628
Banner Corporation Share Repurchase Plan [Member]
Stock repurchases
Stock Repurchase Program, Number of Shares Authorized to be Repurchased		1,711,540
Stock Repurchase Program, Number of Shares Authorized to be Repurchased, Percent of Total Outstanding		5.00%
Stock trading plan, number of shares to be repurchased	1,300,000
Stock Repurchased During Period, Shares	1,145,250
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	566,290

CALCULATION OF EARNINGS PER 109

CALCULATION OF EARNINGS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
NET INCOME AVAILABLE TO COMMON SHAREHOLDERS													$ 85,385	$ 45,222	$ 54,070
Weighted average number of common shares outstanding
Basic weighted average shares outstanding (in shares)													33,820,148	23,801,373	19,359,409
Diluted weighted shares outstanding (in shares)													33,853,511	23,866,621	19,402,656
Earnings per common share
Basic (in dollars per share)	$ 0.69	$ 0.70	$ 0.62	$ 0.52	$ 0.20	$ 0.62	$ 0.64	$ 0.61	$ 0.60	$ 0.76	$ 0.88	$ 0.55	$ 2.52	$ 1.90	$ 2.79
Diluted (in dollars per share)	$ 0.69	$ 0.70	$ 0.61	$ 0.52	$ 0.20	$ 0.62	$ 0.64	$ 0.61	$ 0.60	$ 0.76	$ 0.88	$ 0.54	$ 2.52	$ 1.89	$ 2.79

CALCULATION OF EARNINGS PER 110

CALCULATION OF EARNINGS PER COMMON SHARE (Textuals) (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Unvested restricted stock shares included in computation of diluted earnings per share	290,719	231,562	195,106
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	5,000
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	243,998

SELECTED QUARTERLY FINANCIAL111

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Selected Quarterly Financial Information [Abstract]
Interest income	$ 101,007	$ 97,849	$ 97,321	$ 95,301	$ 96,495	$ 54,793	$ 54,076	$ 49,069	$ 49,251	$ 49,764	$ 46,540	$ 45,106	$ 391,477	$ 254,433	$ 190,661
Interest expense	3,836	4,141	4,173	4,258	4,396	2,605	2,619	2,533	2,590	2,700	2,732	2,767	16,408	12,154	10,789
Interest-bearing deposits	97,171	93,708	93,148	91,043	92,099	52,188	51,457	46,536	46,661	47,064	43,808	42,339	375,069	242,279	179,872
Provision for loan losses	2,030	2,000	2,000	0	0	0	0	0	0	0	0	0	6,030	0	0
Net interest income	95,141	91,708	91,148	91,043	92,099	52,188	51,457	46,536	46,661	47,064	43,808	42,339	369,039	242,279	179,872
Non-interest income	19,463	23,512	20,537	19,959	18,356	14,098	16,141	13,696	12,113	13,536	20,310	9,032	83,470	62,292	54,991
Other operating expenses	79,857	79,092	79,887	84,034	100,254	46,697	47,734	41,914	41,230	38,495	38,435	35,581	322,869	236,600	153,741
Income before provision for income taxes	34,747	36,128	31,798	26,968	10,201	19,589	19,864	18,318	17,544	22,105	25,683	15,790	129,640	67,971	81,122
PROVISION FOR INCOME TAXES	11,943	12,277	10,841	9,194	3,308	6,642	6,615	6,184	5,831	7,284	8,696	5,241	44,255	22,749	27,052
NET INCOME	$ 22,804	$ 23,851	$ 20,957	$ 17,774	$ 6,893	$ 12,947	$ 13,249	$ 12,134	$ 11,713	$ 14,821	$ 16,987	$ 10,549	$ 85,385	$ 45,222	$ 54,070
Basic earnings (loss) per share (in dollars per share)	$ 0.69	$ 0.70	$ 0.62	$ 0.52	$ 0.20	$ 0.62	$ 0.64	$ 0.61	$ 0.60	$ 0.76	$ 0.88	$ 0.55	$ 2.52	$ 1.90	$ 2.79
Diluted earnings (loss) per share (in dollars per share)	0.69	0.70	0.61	0.52	0.20	0.62	0.64	0.61	0.60	0.76	0.88	0.54	2.52	1.89	2.79
Cumulative dividends declared per common share (in dollars per share)	$ 0.23	$ 0.23	$ 0.21	$ 0.21	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.88	$ 0.72	$ 0.72

COMMITMENTS AND CONTINGENCIE112

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Reserve for Unfunded Loan Commitments	$ 3,600		$ 3,900
Mortgage loan applications, day Interest rate is locked	45 days
Minimum [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Mortgage loan applications, day Interest rate is locked	30 days
Maximum [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Mortgage loan applications, day Interest rate is locked	60 days
Commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount		$ 2,204,795	2,132,996
Standby letters of credit and financial guarantees
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount		17,694	22,315
Commitments to originate loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount		69,833	32,908
Risk Participation Agreement [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount		7,488	7,672
Commitments to originate loans held for sale
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount		69,487	76,146
Commitments to sell loans secured by one- to four-family residential properties
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount		36,907	37,545
Loss on Contract Termination for Default	$ 0
Commitments to sell securities related to mortgage banking activities
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount		$ 44,000	$ 41,500

DERIVATIVES AND HEDGING DERI113

DERIVATIVES AND HEDGING DERIVATIVES AND HEDGING (Derivatives Designated as Hedging, by Balance Sheet Location) (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 8,330	$ 11,984
Derivative Liability, Fair Value, Gross Liability		8,330	11,984
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		8,330	11,984
Derivative Liability, Fair Value, Gross Liability		8,330	11,984
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount		5,855	6,734
Derivative Liability, Notional Amount		5,855	6,734
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Loans Receivable [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	660	938
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	[2]	$ 660	$ 938
[1]	Included in Loans Receivable on the Consolidated Statements of Financial Condition.
[2]	Included in Other Liabilities on the Consolidated Statements of Financial Condition.

DERIVATIVES AND HEDGING DERI114

DERIVATIVES AND HEDGING DERIVATIVES AND HEDGING (Derivatives Not Designated as Hedging, by Balance Sheet Location) (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 8,330	$ 11,984
Derivative Liability, Fair Value, Gross Liability		8,330	11,984
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		8,330	11,984
Derivative Liability, Fair Value, Gross Liability		8,330	11,984
Interest Rate Swap [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount		307,100
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount		423,424	411,583
Derivative Liability, Notional Amount		346,842	326,700
Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	8,152	11,517
Not Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	[2]	7,959	11,096
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount		309,936	293,937
Derivative Liability, Notional Amount		309,936	293,937
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Loans Receivable [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		822	327
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	7,670	11,046
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	[2]	7,670	11,046
Not Designated as Hedging Instrument [Member] | Mortgage Loan Commitments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount		42,296	76,146
Derivative Liability, Notional Amount		27,191	0
Not Designated as Hedging Instrument [Member] | Mortgage Loan Commitments [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	30	428
Not Designated as Hedging Instrument [Member] | Mortgage Loan Commitments [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	[2]	174	0
Not Designated as Hedging Instrument [Member] | Forward Sales Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount		71,192	41,500
Derivative Liability, Notional Amount		9,715	32,763
Not Designated as Hedging Instrument [Member] | Forward Sales Contracts [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	452	43
Not Designated as Hedging Instrument [Member] | Forward Sales Contracts [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	[2]	$ 115	$ 50
[1]	Included in Other Assets on the Consolidated Statements of Financial Condition, with the exception of those interest rate swaps from prior to 2009 that were not designated in hedge relationships (with a fair value of $822,000 at December 31, 2016 and $327,000 at December 31, 2015), which are included in Loans Receivable.
[2]	Included in Other Liabilities on the Consolidated Statements of Financial Condition.

DERIVATIVES AND HEDGING DERI115

DERIVATIVES AND HEDGING DERIVATIVES AND HEDGING (Gain (Loss) On Derivatives Not Designated in Hedging Relationship) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ (52)	$ 241
Mortgage Loan Commitments [Member] | Mortgage Banking Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(348)	100
Forward Sales Contracts [Member] | Mortgage Banking Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 296	$ 141

DERIVATIVES AND HEDGING DERI116

DERIVATIVES AND HEDGING DERIVATIVES AND HEDGING (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative, Net Liability Position, Aggregate Fair Value	$ 7.6	$ 12
Collateral Already Posted, Aggregate Fair Value	$ 29.3	$ 20.8

DERIVATIVES AND HEDGING DERI117

DERIVATIVES AND HEDGING DERIVATIVES AND HEDGING (Derivative Offsetting) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Offsetting Assets and Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 8,330	$ 11,984
Derivative Asset, Fair Value, Gross Liability	0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	8,330	11,984
Derivative, Collateral, Obligation to Return Securities	(362)	0
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	7,968	11,984
Derivative Liability, Fair Value, Gross Liability	8,330	11,984
Derivative Liability, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	8,330	11,984
Derivative, Collateral, Right to Reclaim Securities	(362)	0
Derivative, Collateral, Right to Reclaim Cash	(7,557)	(11,984)
Derivative Liability, Fair Value, Amount Offset Against Collateral	411	0
Interest Rate Swap [Member]
Offsetting Assets and Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	8,330	11,984
Derivative Asset, Fair Value, Gross Liability	0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	8,330	11,984
Derivative, Collateral, Obligation to Return Securities	(362)	0
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	7,968	11,984
Derivative Liability, Fair Value, Gross Liability	8,330	11,984
Derivative Liability, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	8,330	11,984
Derivative, Collateral, Right to Reclaim Securities	(362)	0
Derivative, Collateral, Right to Reclaim Cash	(7,557)	(11,984)
Derivative Liability, Fair Value, Amount Offset Against Collateral	$ 411	$ 0