Banner (BANR) 10-Q 2 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	6 Months Ended
	Jun. 30, 2019	Jul. 31, 2019
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $.01 per share
Trading Symbol	BANR
Security Exchange Name	NASDAQ
Entity Registrant Name	BANNER CORPORATION
Entity Incorporation, State or Country Code	WA
Entity Tax Identification Number	91-1691604
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	000-26584
Amendment Flag	false
Entity Central Index Key	0000946673
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Entity Address, Address Line One	10 South First Avenue
Entity Address, City or Town	Walla Walla
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	99362
City Area Code	509
Local Phone Number	527-3636
Voting Common Stock [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		34,534,184
Nonvoting Common Stock [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		39,192

CONSOLIDATED STATEMENTS OF FINA

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
ASSETS
Cash and due from banks		$ 187,043	$ 231,029
Interest bearing deposits		59,753	41,167
Total cash and cash equivalents		246,796	272,196
Securities—trading		25,741	25,896
Securities—available-for-sale, amortized cost $1,535,775 and $1,648,421, respectively		1,561,009	1,636,223
Securities—held-to-maturity, fair value $206,917 and $232,537, respectively		203,222	234,220
Total securities		1,789,972	1,896,339
Federal Home Loan Bank (FHLB) stock		34,583	31,955
Loans held for sale (includes $149.7 million and $164.8 million, at fair value, respectively)		170,744	171,031
Loans receivable		8,746,550	8,684,595
Allowance for loan losses		98,254	96,485
Loans and Leases Receivable, Net Amount		8,648,296	8,588,110
Accrued interest receivable		40,238	38,593
Real estate owned (REO), held for sale, net		2,513	2,611
Property and equipment, net		171,233	171,809
Goodwill		339,154	339,154
Other intangibles, net		28,595	32,924
Bank-owned life insurance (BOLI)		178,922	177,467
Deferred tax assets, net		61,327	75,020
Other assets		135,001	74,108
Total assets		11,847,374	11,871,317
Deposits:
Non-interest-bearing		3,671,995	3,657,817
Interest-bearing transaction and savings accounts		4,546,202	4,498,966
Interest-bearing certificates	[1]	1,070,770	1,320,265
Total deposits		9,288,967	9,477,048
Advances from FHLB		606,000	540,189
Other borrowings		118,370	118,995
Junior subordinated debentures at fair value (issued in connection with Trust Preferred Securities)		113,621	114,091
Accrued expenses and other liabilities		159,131	102,061
Deferred compensation		40,230	40,338
Total liabilities		10,326,319	10,392,722
COMMITMENTS AND CONTINGENCIES (Note 13)
SHAREHOLDERS’ EQUITY
Preferred stock - $0.01 par value per share, 500,000 shares authorized; no shares outstanding at June 30, 2019 and December 31, 2018		0	0
Retained earnings		178,257	134,055
Carrying value of shares held in trust for stock-based compensation plans		(7,324)	(7,289)
Liability for common stock issued to stock related compensation plans		7,324	7,289
Accumulated other comprehensive income		35,910	7,104
Total shareholders' equity		1,521,055	1,478,595
Total liabilities and shareholders' equity		11,847,374	11,871,317
Voting Common Stock [Member]
SHAREHOLDERS’ EQUITY
Common stock and paid in capital		1,306,000	1,336,030
Nonvoting Common Stock [Member]
SHAREHOLDERS’ EQUITY
Common stock and paid in capital		$ 888	$ 1,406
[1]	Certificates of deposit include $384,000 and $563,000 of acquisition premiums at June 30, 2019 and December 31, 2018 , respectively.

CONSOLIDATED STATEMENTS OF FI_2

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
ASSETS
Securities—trading, amortized cost basis	$ 27,203	$ 27,203
Securities—available-for-sale, amortized cost basis	1,535,775	1,648,421
Securities—held-to-maturity, fair value	$ 206,917	$ 232,537
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	0	35,107,839
Common stock, shares outstanding	0	35,107,839
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	0	74,933
Common stock, shares outstanding	0	74,933
Loans [Member] | Recurring [Member]
ASSETS
Loans Held-for-sale, Fair Value Disclosure	$ 149,691	$ 164,767

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Acquisition-related costs	$ 301	$ 0	$ 2,449	$ 0
INTEREST INCOME:
Loans receivable	117,007	99,853	232,462	193,875
Mortgage-backed securities	9,794	8,899	20,301	16,230
Securities and cash equivalents	4,037	3,671	8,071	7,138
Total interest income	130,838	112,423	260,834	217,243
INTEREST EXPENSE:
Deposits	9,023	4,264	17,666	7,622
FHLB advances	3,370	1,499	6,846	2,177
Other borrowings	67	49	127	119
Junior subordinated debentures	1,683	1,548	3,396	2,889
Total interest expense	14,143	7,360	28,035	12,807
Net interest income	116,695	105,063	232,799	204,436
PROVISION FOR LOAN LOSSES	2,000	2,000	4,000	4,000
Net interest income after provision for loan losses	114,695	103,063	228,799	200,436
NON-INTEREST INCOME:
Deposit fees and other service charges	14,046	11,985	26,664	23,281
Bank-owned life insurance (BOLI)	1,123	933	2,399	1,785
Miscellaneous	1,713	3,388	2,517	4,426
Other operating income	22,818	20,949	40,931	38,999
Net (loss) gain on sale of securities	(28)	44	(27)	48
Net change in valuation of financial instruments carried at fair value	(114)	224	(103)	3,532
Total non-interest income	22,676	21,217	40,801	42,579
NON-INTEREST EXPENSE:
Salary and employee benefits	55,629	51,494	110,269	101,561
Less capitalized loan origination costs	(7,399)	(4,733)	(12,248)	(8,744)
Occupancy and equipment	12,681	11,574	26,447	23,340
Information/computer data services	5,273	4,564	10,599	8,945
Payment and card processing expenses	4,041	3,731	8,025	7,431
Professional and legal expenses	2,336	3,838	4,770	8,266
Advertising and marketing	2,065	2,141	3,594	3,971
Deposit insurance	1,418	1,021	2,836	2,362
State/municipal business and use taxes	1,007	816	1,952	1,529
REO operations, net	260	(319)	137	121
Amortization of core deposit intangibles	2,053	1,382	4,105	2,764
Miscellaneous	7,051	7,128	13,795	12,797
Total non-interest expense	86,716	82,637	176,730	164,343
Noninterest Operating Expense, Before Acquisition Related Costs	86,415	82,637	174,281	164,343
Income before provision for income taxes	50,655	41,643	92,870	78,672
PROVISION FOR INCOME TAXES	10,955	9,219	19,824	17,458
NET INCOME	$ 39,700	$ 32,424	$ 73,046	$ 61,214
Earnings per common share:
Basic	$ 1.14	$ 1.01	$ 2.09	$ 1.89
Diluted	1.14	1	2.09	1.89
Cumulative dividends declared per common share	$ 0.41	$ 0.85	$ 0.82	$ 1.20
Weighted average number of common shares outstanding, Basic	34,831,047	32,250,514	34,940,106	32,323,635
Weighted average number of common shares outstanding, Diluted	34,882,359	32,331,609	35,028,881	32,422,287
Mortgage Banking [Member]
NON-INTEREST INCOME:
Mortgage banking operations	$ 5,936	$ 4,643	$ 9,351	$ 9,507

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 39,700	$ 32,424	$ 73,046	$ 61,214
OTHER COMPREHENSIVE INCOME (LOSS), NET OF INCOME TAXES:
Unrealized holding gain (loss) on available-for-sale securities arising during the period	20,751	(8,305)	37,407	(23,073)
Reclassification for net loss (gain) on available-for-sale securities realized in earnings	27	(49)	26	(51)
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, before Tax, after Reclassification Adjustment	296	(258)	470	(14,067)
Income tax related to other comprehensive (loss) income	(5,058)	2,091	(9,097)	8,893
Other comprehensive income (loss)	16,016	(6,521)	28,806	(28,298)
COMPREHENSIVE INCOME	$ 55,716	$ 25,903	$ 101,852	$ 32,916

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Common Stock and Paid in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of reclassification of the instrument-specific credit risk portion of junior subordinated debentures fair value adjustments and reclassification of equity securities from available-for-sale	$ 0			$ (28,203)	$ 28,203
Balance, beginning of the period at Dec. 31, 2017	1,272,626		$ 1,187,127	90,535	(5,036)
Balance, beginning of the period (in shares) at Dec. 31, 2017		32,726,485
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	28,790			28,790
Other comprehensive income, net of income tax	(21,777)				(21,777)
Repurchase of common stock	(15,359)		(15,359)
Repurchase of common stock (in shares)		(269,711)
Accrual of dividends on common stock	(11,349)			(11,349)
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered	1,192		1,192
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered (in shares)		(33,101)
Balance, end of the period at Mar. 31, 2018	1,254,123		1,172,960	79,773	1,390
Balance, end of the period (in shares) at Mar. 31, 2018		32,423,673
Balance, beginning of the period at Dec. 31, 2017	1,272,626		1,187,127	90,535	(5,036)
Balance, beginning of the period (in shares) at Dec. 31, 2017		32,726,485
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	61,214
Balance, end of the period at Jun. 30, 2018	1,253,010		1,173,656	84,485	(5,131)
Balance, end of the period (in shares) at Jun. 30, 2018		32,405,696
Balance, beginning of the period at Mar. 31, 2018	1,254,123		1,172,960	79,773	1,390
Balance, beginning of the period (in shares) at Mar. 31, 2018		32,423,673
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	32,424			32,424
Other comprehensive income, net of income tax	(6,521)				(6,521)
Accrual of dividends on common stock	(27,712)			(27,712)
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered	696		696
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered (in shares)		(17,977)
Balance, end of the period at Jun. 30, 2018	1,253,010		1,173,656	84,485	(5,131)
Balance, end of the period (in shares) at Jun. 30, 2018		32,405,696
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	37,773			37,773
Other comprehensive income, net of income tax	(7,863)				(7,863)
Accrual of dividends on common stock	(12,316)			(12,316)
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered	1,594		1,594
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered (in shares)		(2,939)
Balance, end of the period at Sep. 30, 2018	1,272,198		1,175,250	109,942	(12,994)
Balance, end of the period (in shares) at Sep. 30, 2018		32,402,757
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	37,527			37,527
Other comprehensive income, net of income tax	20,098				20,098
Repurchase of common stock	(19,042)		(19,042)
Repurchase of common stock (in shares)		(325,000)
Accrual of dividends on common stock	(13,414)			(13,414)
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered	1,519		1,519
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered (in shares)		(3,056)
Business acquisition	179,709		179,709
Business acquisition (in shares)		3,108,071
Balance, end of the period at Dec. 31, 2018	1,478,595		1,337,436	134,055	7,104
Balance, end of the period (in shares) at Dec. 31, 2018		35,182,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	33,346			33,346
Other comprehensive income, net of income tax	12,790				12,790
Accrual of dividends on common stock	(14,490)			(14,490)
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered	950		950
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered (in shares)		(30,026)
Balance, end of the period at Mar. 31, 2019	1,511,191		1,338,386	152,911	19,894
Balance, end of the period (in shares) at Mar. 31, 2019		35,152,746
Balance, beginning of the period at Dec. 31, 2018	1,478,595		1,337,436	134,055	7,104
Balance, beginning of the period (in shares) at Dec. 31, 2018		35,182,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	73,046
Balance, end of the period at Jun. 30, 2019	1,521,055		1,306,888	178,257	35,910
Balance, end of the period (in shares) at Jun. 30, 2019		34,573,643
Balance, beginning of the period at Mar. 31, 2019	1,511,191		1,338,386	152,911	19,894
Balance, beginning of the period (in shares) at Mar. 31, 2019		35,152,746
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	39,700			39,700
Other comprehensive income, net of income tax	16,016				16,016
Repurchase of common stock	(32,073)		(32,073)
Repurchase of common stock (in shares)		(600,000)
Accrual of dividends on common stock	(14,354)			(14,354)
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered	575		575
Amortization of stock-based compensation related to restricted stock grants, net of shares surrendered (in shares)		20,897
Balance, end of the period at Jun. 30, 2019	$ 1,521,055		$ 1,306,888	$ 178,257	$ 35,910
Balance, end of the period (in shares) at Jun. 30, 2019		34,573,643

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended					6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Stockholders' Equity [Abstract]
Cumulative dividends declared per common share	$ 0.41	$ 0.38	$ 0.38	$ 0.85	$ 0.35	$ 0.82	$ 1.20

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Statement of Cash Flows [Abstract]
Net cash paid related to branch divestiture	$ 0	$ 20,412
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0	249
OPERATING ACTIVITIES:
Net income	73,046	61,214
Adjustments to reconcile net income to net cash provided from operating activities:
Depreciation	8,747	7,253
Deferred income and expense, net of amortization	(647)	(1,518)
Amortization of core deposit intangibles	4,105	2,764
Loss (gain) on sale of securities	27	(48)
Net change in valuation of financial instruments carried at fair value	103	(3,532)
Decrease (increase) in deferred taxes	(13,693)	6,510
Increase in current taxes payable	943	5,603
Stock-based compensation	3,394	3,231
Increase in cash surrender value of BOLI	(2,382)	(1,768)
Gain on sale of loans, net of capitalized servicing rights	(6,730)	(6,533)
Loss (gain) on disposal of real estate held for sale and property and equipment	721	(1,858)
Provision for loan losses	4,000	4,000
Provision for losses on real estate held for sale	0	160
Origination of loans held for sale	(397,227)	(415,790)
Proceeds from sales of loans held for sale	404,244	384,215
Net change in:
Other assets	(12,131)	1,734
Other liabilities	(5,911)	1,797
Net cash provided from operating activities	87,995	34,165
INVESTING ACTIVITIES:
Purchases of securities—available-for-sale	(52,525)	(591,265)
Principal repayments and maturities of securities—available-for-sale	120,638	69,853
Proceeds from sales of securities—available-for-sale	40,759	8,363
Purchases of securities—held-to-maturity	0	(8,469)
Principal repayments and maturities of securities—held-to-maturity	29,936	4,422
Loan originations, net of principal repayments	(64,641)	(82,461)
Purchases of loans and participating interest in loans	(777)	(2,268)
Proceeds from sales of other loans	7,155	4,733
Purchases of property and equipment	(11,759)	(9,925)
Proceeds from sale of real estate held for sale and sale of other property, net	4,243	6,367
Proceeds from FHLB stock repurchase program	90,373	79,878
Purchase of FHLB stock	(93,000)	(89,460)
Other	947	417
Net cash provided from (used in) investing activities	71,349	(630,227)
FINANCING ACTIVITIES:
(Decrease) increase in deposits, net	(188,081)	364,890
Proceeds from FHLBank Advance, Investing Activities	300,000	0
Repayments of long-term Federal Home Loan Bank Advances	(189)	(5)
(Repayment) proceeds from overnight and short term FHLB advances, net	(234,000)	239,000
(Decrease) Increase in other borrowings, net	(626)	16,598
Cash dividends paid	(27,906)	(19,494)
Taxes paid related to net share settlement of equity awards	1,869	1,343
Payments for Repurchase of Common Stock	32,073	15,359
Net cash (used in) provided from financing activities	(184,744)	584,287
NET CHANGE IN CASH AND CASH EQUIVALENTS	(25,400)	(11,775)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	272,196	261,200
CASH AND CASH EQUIVALENTS, END OF PERIOD	246,796	249,425
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest paid in cash	29,892	11,720
Tax paid, net	13,477	8,806
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	154	1,419
Dividends Payable	$ 14,714	$ 27,833

BASIS OF PRESENTATION AND SIGNI

BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES	BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES The accompanying unaudited condensed consolidated financial statements include the accounts of Banner Corporation (the Company or Banner), a bank holding company incorporated in the State of Washington and its wholly-owned subsidiaries, Banner Bank and Islanders Bank (the Banks). These unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP) for interim financial information and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X as promulgated by the Securities and Exchange Commission (SEC). In preparing these financial statements, the Company has evaluated events and transactions subsequent to June 30, 2019 for potential recognition or disclosure. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of the financial position and results of operations for the periods presented have been included. Certain information and disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations of the SEC and the accounting standards for interim financial statements. Certain reclassifications have been made to the 2018 Consolidated Financial Statements and/or schedules to conform to the 2019 presentation. These reclassifications may have affected certain ratios for the prior periods. The effect of these reclassifications is considered immaterial. All significant intercompany transactions and balances have been eliminated. 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 significant 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 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 of assets acquired and liabilities assumed in business combinations and subsequent recognition of related income and expense, and (vii) the valuation or recognition of deferred tax assets and liabilities. These policies and judgments, estimates and assumptions are described in greater detail in subsequent notes to the Consolidated Financial Statements and Management’s Discussion and Analysis of Financial Condition and Results of Operations (Critical Accounting Policies) in our Annual Report on Form 10-K for the year ended December 31, 2018 filed with the SEC (2018 Form 10-K). There have been no significant changes in our application of these accounting policies during the first six months of 2019 , except as described in Note 2. On July 25, 2019, Banner and AltaPacific Bancorp, Inc. (“AltaPacific”), the holding company for AltaPacific Bank, a California state-chartered commercial bank, announced that they have entered into a definitive merger agreement pursuant to which Banner will acquire AltaPacific in an all-stock transaction, subject to the terms and conditions set forth therein. Under the merger agreement, AltaPacific will merge with and into Banner, and immediately thereafter AltaPacific Bank will merge with and into Banner Bank. The combined company will have approximately $12.2 billion in assets. See Note 17 for additional information on the transaction. The information included in this Form 10-Q should be read in conjunction with our 2018 Form 10-K. Interim results are not necessarily indicative of results for a full year or any other interim period.

ACCOUNTING STANDARDS RECENTLY I

ACCOUNTING STANDARDS RECENTLY ISSUED OR ADOPTED	6 Months Ended
	Jun. 30, 2019
Accounting Changes and Error Corrections [Abstract]
ACCOUNTING STANDARDS RECENTLY ISSUED OR ADOPTED	ACCOUNTING STANDARDS RECENTLY ISSUED OR ADOPTED Leases (Topic 842) In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (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 leases) 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. In July 2018, FASB issued ASU No. 2018-11, Targeted Improvements . The amendments in this ASU provide entities with an additional (and optional) transition method to adopt the new leases standard. The Company adopted the requirements of Topic 842 effective January 1, 2019. The Company elected the transition option provided in ASU No. 2018-11 and applied the modified retrospective approach for leases that existed as of January 1, 2019, or were entered into thereafter. The Company elected certain relief options for practical expedients: the option to not separate lease and non-lease components and instead to account for them as a single lease component, and the option to not recognize right-of-use assets and lease liabilities that arise from short-term leases (i.e. lease terms of twelve months or less). In addition, the Company elected the package of practical expedients in transition, which permitted us to not reassess our prior conclusions pertaining to lease identification, lease classification, and initial direct costs on leases that commenced prior to our adoption of the new standard. In connection with the adoption of this ASU, as of January 1, 2019, the Company recorded a $56 million right-of-use asset and a $59 million lease liability on its Consolidated Statements of Financial Condition. 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 ASU affects loans, debt securities, trade receivables, net investments in leases, off-balance-sheet credit exposures, reinsurance receivables, and any other financial asset not excluded from the scope that have the contractual right to receive cash. The ASU replaces 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. This ASU requires 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. This ASU broadens 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. 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. The Company has formed an internal committee to oversee the project, engaged a third-party vendor to assist with the project and has completed its gap analysis phase of the project. In addition, the Company has selected a second third-party vendor to assist with building and developing the required models and has completed the initial build out of the required models. The Company has also selected a different third-party to provide a reasonable and supportable forecast. The Company is in the process of incorporating the reasonable and supportable forecast and qualitative factors into the models. Upon adoption, the Company expects changes in the processes and procedures used to calculate the allowance for loan losses, including changes in assumptions and estimates to consider expected credit losses over the life of the loan versus the current accounting practice that utilizes the incurred loss model. The new guidance may result in an increase in the allowance for loan losses which will also reflect the new requirement to include the nonaccretable principal differences on purchased credit-impaired loans; however, the Company is still in the process of determining the magnitude of the change and its impact on the Consolidated Financial Statements. In addition, the current accounting policy and procedures for other-than-temporary impairment on investment securities available-for-sale will be replaced with an allowance approach. Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20) In March 2017, FASB issued ASU No. 2017-08, Premium Amortization on Purchased Callable Debt Securities . The amendments in this ASU shorten the premium amortization period for callable debt securities purchased at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. Under current GAAP, premiums and discounts on callable debt securities generally are amortized to the maturity date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to the maturity date. The amendments in this ASU more closely align the amortization period of premiums and discounts to expectations incorporated in market pricing on the underlying securities. The amendments in this ASU are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. The Company adopted this ASU effective January 1, 2019. The adoption of this ASU has not had a material impact on the Company’s Consolidated Financial Statements. Derivatives and Hedging (Topic 815) In August 2017, FASB issued ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities . The amendments in this ASU are intended to provide investors better insight into an entity's risk management hedging strategies by permitting a company to recognize the economic results of its hedging strategies in its financial statements. The amendments in this ASU permit hedge accounting for hedging relationships involving non-financial risk and interest rate risk by removing certain limitations in cash flow and fair value hedging relationships. In addition, the ASU requires an entity to present the earnings effect of the hedging instrument in the same income statement line item in which the earnings effect of the hedged item is reported. This ASU is effective for fiscal years beginning after December 15, 2018. Adoption of ASU 2017-12 did not have a material impact on the Company's Consolidated Financial Statements. Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40) In August 2018, FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract . The amendments in this ASU broaden the scope of ASC Subtopic 350-40 to include costs incurred to implement a hosting arrangement that is a service contract. The amendments align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The costs are capitalized or expensed depending on the nature of the costs and the project stage during which they are incurred, consistent with the accounting for costs for internal-use software. The amendments in this ASU result in consistent capitalization of implementation costs of a hosting arrangement that is a service contract and implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by the amendments in this ASU. This ASU is effective for fiscal years beginning after December 15, 2019 and interim periods within those fiscal years. The amendments in this ASU should be applied either retrospectively to all implementation costs incurred after the date of adoption. Adoption of ASU 2018-15 is not expected to have a material impact on the Company’s Consolidated Financial Statements. Fair Value Measurement (Topic 820) In August 2018, FASB issued ASU 2018-13, Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement . The amendments in this ASU modify the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement. The ASU removes, modifies and adds disclosure requirements in Topic 820. The following disclosure requirements were removed: 1) the amount and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, 2) the policy for timing of transfers between levels, and 3) the valuation processes for Level 3 fair value measurements. This ASU modified disclosure requirements by requiring: that the measurement uncertainty disclosure communicates information about the uncertainty in measurement as of the reporting date. The following disclosure requirements were added: 1) changes in unrealized gains and losses for the period included in other comprehensive income for the recurring Level 3 fair value measurements held at the end of the reporting period, and 2) the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The amendments in this ASU are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. An entity is permitted to early adopt any removed or modified disclosures upon issuance of this ASU and delay adoption of the additional disclosures until their effective date. Adoption of ASU 2018-13 is not expected to have a material impact on the Company’s Consolidated Financial Statements.

BUSINESS COMBINATION

BUSINESS COMBINATION	6 Months Ended
	Jun. 30, 2019
Business Combinations [Abstract]
BUSINESS COMBINATION	BUSINESS COMBINATION Acquisition of Skagit Bancorp, Inc. Effective as of the close of business on November 1, 2018 , the Company acquired 100% of the outstanding common shares of Skagit Bancorp, Inc. (“Skagit”) and its wholly-owned subsidiary, Skagit Bank, a Washington State chartered commercial bank headquartered in Burlington, Washington, with 11 branches serving markets along the I-5 corridor from Seattle to the Canadian border. On that date, Skagit merged with and into Banner and Skagit Bank merged with and into Banner Bank. Pursuant to the previously announced terms of the merger, the equity holders of Skagit received an aggregate of 3.1 million shares of Banner voting common stock, plus cash in lieu of fractional shares and to cancel Skagit stock options, for total consideration paid of $180.0 million . The acquisition provided $915.8 million in assets, $810.2 million in deposits and $632.4 million in loans to Banner. The application of the acquisition method of accounting resulted in recognition of a CDI asset of $16.4 million and goodwill of $96.5 million . The acquired CDI has been determined to have a useful life of approximately nine 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): Skagit November 1, 2018 Consideration to Skagit equity holders: Cash paid $ 329 Fair value of common shares issued 179,709 Total consideration $ 180,038 Fair value of assets acquired: Cash and cash equivalents $ 19,167 Securities 210,326 Loans receivable (contractual amount of $645.6 million) 632,374 Real estate owned held for sale 2,593 Property and equipment 15,788 Core deposit intangible 16,368 Deferred tax asset 95 Other assets 19,110 Total assets acquired 915,821 Fair value of liabilities assumed: Deposits 810,209 Other liabilities 22,069 Total liabilities assumed 832,278 Net assets acquired 83,543 Goodwill $ 96,495 Acquired goodwill represents the premium the Company paid over the fair value of the net tangible and intangible assets acquired. The primary reason for the acquisition was to expand the Company’s presence and density in the North Sound region of the Pacific Northwest along the I-5 corridor. 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 existing markets. See Note 7, Goodwill, Other Intangible Assets and Mortgage Servicing Rights for the accounting for goodwill and other intangible assets. Fair values are preliminary and subject to refinement for up to one year after the closing date of the acquisition as additional information regarding the closing date fair values becomes available. Additional adjustments to the acquisition accounting that may be required would most likely involve loans, property and equipment, or the deferred tax asset. As of November 1, 2018, the unpaid principal balance on purchased non-credit-impaired loans was $637.4 million . The fair value of the purchased non-credit-impaired loans was $625.2 million , resulting in a discount of $12.2 million recorded on these loans, which includes $7.9 million of a credit related discount. 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): Skagit November 1, 2018 Acquired PCI loans: Contractually required principal and interest payments $ 9,897 Nonaccretable difference (1,915 ) Cash flows expected to be collected 7,982 Accretable yield (995 ) Fair value of PCI loans $ 6,987 The operating results of the Company include the operating results produced by the acquired assets and assumed liabilities of Skagit for the period since November 1, 2018. Disclosure of the amount of Skagit’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. The pro forma impact of the Skagit acquisition to the historical financial results was determined to not be significant.

SECURITIES

SECURITIES	6 Months Ended
	Jun. 30, 2019
Investments, Debt and Equity Securities [Abstract]
INTEREST-BEARING DEPOSITS AND SECURITIES	SECURITIES The amortized cost, gross unrealized gains and losses and estimated fair value of securities at June 30, 2019 and December 31, 2018 are summarized as follows (in thousands): June 30, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Trading: Corporate bonds $ 27,203 $ 25,741 $ 27,203 $ 25,741 Available-for-Sale: U.S. Government and agency obligations $ 125,597 $ 437 $ (966 ) $ 125,068 Municipal bonds 106,379 4,549 (18 ) 110,910 Corporate bonds 4,557 12 (8 ) 4,561 Mortgage-backed or related securities 1,291,166 22,751 (1,484 ) 1,312,433 Asset-backed securities 8,076 2 (41 ) 8,037 $ 1,535,775 $ 27,751 $ (2,517 ) $ 1,561,009 Held-to-Maturity: U.S. Government and agency obligations $ 388 $ 6 $ — $ 394 Municipal bonds 148,580 3,538 (629 ) 151,489 Corporate bonds 3,668 — (12 ) 3,656 Mortgage-backed or related securities 50,586 821 (29 ) 51,378 $ 203,222 $ 4,365 $ (670 ) $ 206,917 December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Trading: Corporate bonds $ 27,203 $ 25,896 $ 27,203 $ 25,896 Available-for-Sale: U.S. Government and agency obligations $ 151,012 $ 149 $ (2,049 ) $ 149,112 Municipal bonds 116,548 1,806 (532 ) 117,822 Corporate bonds 3,556 — (61 ) 3,495 Mortgage-backed or related securities 1,355,258 5,210 (16,607 ) 1,343,861 Asset-backed securities 22,047 6 (120 ) 21,933 $ 1,648,421 $ 7,171 $ (19,369 ) $ 1,636,223 Held-to-Maturity: U.S. Government and agency obligations $ 1,006 $ 14 $ (1 ) $ 1,019 Municipal bonds 176,663 1,727 (2,578 ) 175,812 Corporate bonds 3,736 — (13 ) 3,723 Mortgage-backed or related securities 52,815 66 (898 ) 51,983 $ 234,220 $ 1,807 $ (3,490 ) $ 232,537 At June 30, 2019 and December 31, 2018 , 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 were as follows (in thousands): June 30, 2019 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 $ — $ — $ 71,611 $ (966 ) $ 71,611 $ (966 ) Municipal bonds 493 (3 ) 3,230 (15 ) 3,723 (18 ) Corporate bonds 352 (1 ) 1,798 (7 ) 2,150 (8 ) Mortgage-backed or related securities 73,934 (483 ) 207,659 (1,001 ) 281,593 (1,484 ) Asset-backed securities 7,314 (40 ) 229 (1 ) 7,543 (41 ) $ 82,093 $ (527 ) $ 284,527 $ (1,990 ) $ 366,620 $ (2,517 ) Held-to-Maturity Municipal bonds $ — $ — $ 23,378 $ (629 ) $ 23,378 $ (629 ) Corporate bonds — — 488 (12 ) 488 (12 ) Mortgage-backed or related securities 2,211 (1 ) 6,128 (28 ) 8,339 (29 ) $ 2,211 $ (1 ) $ 29,994 $ (669 ) $ 32,205 $ (670 ) December 31, 2018 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 $ 75,885 $ (1,240 ) $ 50,508 $ (809 ) $ 126,393 $ (2,049 ) Municipal bonds 6,422 (54 ) 27,231 (478 ) 33,653 (532 ) Corporate bonds 3,199 (56 ) 295 (5 ) 3,494 (61 ) Mortgage-backed or related securities 316,074 (2,939 ) 571,989 (13,668 ) 888,063 (16,607 ) Asset-backed securities 10,582 (24 ) 9,913 (96 ) 20,495 (120 ) $ 412,162 $ (4,313 ) $ 659,936 $ (15,056 ) $ 1,072,098 $ (19,369 ) Held-to-Maturity U.S. Government and agency obligations $ 145 $ (1 ) $ — $ — $ 145 $ (1 ) Municipal bonds 29,898 (274 ) 44,637 (2,304 ) 74,535 (2,578 ) Corporate bonds — — 487 (13 ) 487 (13 ) Mortgage-backed or related securities 10,761 (220 ) 30,035 (678 ) 40,796 (898 ) $ 40,804 $ (495 ) $ 75,159 $ (2,995 ) $ 115,963 $ (3,490 ) At June 30, 2019 , there were 105 securities—available-for-sale with unrealized losses, compared to 271 at December 31, 2018 . At June 30, 2019 , there were 14 securities—held-to-maturity with unrealized losses, compared to 90 at December 31, 2018 . Management does not believe that any individual unrealized loss as of June 30, 2019 or December 31, 2018 represented other-than-temporary impairment (OTTI). The decline in fair market value of these securities was generally due to changes in interest rates and changes in market-desired spreads subsequent to their purchase. There were no sales of securities—trading during the six -month periods ended June 30, 2019 or 2018 . There were no securities—trading in a nonaccrual status at June 30, 2019 or December 31, 2018 . Net unrealized holding losses of $103,000 were recognized during the six months ended June 30, 2019 compared to $3.4 million of net unrealized holdings gains recognized during the six months ended June 30, 2018 . There were 36 sales of securities—available-for-sale during the six months ended June 30, 2019 , with a net loss of $26,000 . There were nine sales of securities—available-for-sale during the six months ended June 30, 2018 , which together with partial calls of securities resulted in a net gain of $51,000 for the six months ended June 30, 2018 . There were no securities—available-for-sale in a nonaccrual status at June 30, 2019 or December 31, 2018 . There were no sales of securities—held-to-maturity during the six -month period ended June 30, 2019 or 2018 , although there were partial calls of securities that resulted in a net loss of $1,000 for the six -months ended June 30, 2019 and a net gain of $2,000 for the six months ended June 30, 2018 . There were no securities—held-to-maturity in a nonaccrual status at June 30, 2019 or December 31, 2018 . The amortized cost and estimated fair value of securities at June 30, 2019 , 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. June 30, 2019 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 $ — $ — $ 2,554 $ 2,556 $ 4,602 $ 4,604 Maturing after one year through five years — — 57,247 58,238 63,805 64,663 Maturing after five years through ten years — — 393,053 404,449 43,943 45,457 Maturing after ten years through twenty years 27,203 25,741 178,802 183,689 58,805 60,672 Maturing after twenty years — — 904,119 912,077 32,067 31,521 $ 27,203 $ 25,741 $ 1,535,775 $ 1,561,009 $ 203,222 $ 206,917 The following table presents, as of June 30, 2019 , investment securities which were pledged to secure borrowings, public deposits or other obligations as permitted or required by law (in thousands): June 30, 2019 Carrying Value Amortized Cost Fair Value Purpose or beneficiary: State and local governments public deposits $ 136,556 $ 136,217 $ 139,723 Interest rate swap counterparties 15,560 15,494 15,741 Repurchase agreements 144,625 142,411 144,625 Other 2,721 2,721 2,698 Total pledged securities $ 299,462 $ 296,843 $ 302,787

LOANS RECEIVABLE AND THE ALLOWA

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES	6 Months Ended
	Jun. 30, 2019
Receivables [Abstract]
LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES	LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES Loans receivable at June 30, 2019 and December 31, 2018 are summarized as follows (dollars in thousands): June 30, 2019 December 31, 2018 Amount Percent of Total Amount Percent of Total Commercial real estate: Owner-occupied $ 1,433,995 16.4 % $ 1,430,097 16.4 % Investment properties 2,116,306 24.2 2,131,059 24.5 Multifamily real estate 402,241 4.6 368,836 4.2 Commercial construction 172,931 2.0 172,410 2.0 Multifamily construction 189,160 2.2 184,630 2.1 One- to four-family construction 503,061 5.7 534,678 6.2 Land and land development: Residential 187,180 2.1 188,508 2.2 Commercial 27,470 0.3 27,278 0.3 Commercial business 1,598,788 18.3 1,483,614 17.1 Agricultural business, including secured by farmland 380,805 4.3 404,873 4.7 One- to four-family residential 944,617 10.8 973,616 11.2 Consumer: Consumer secured by one- to four-family 575,658 6.6 568,979 6.6 Consumer—other 214,338 2.5 216,017 2.5 Total loans 8,746,550 100.0 % 8,684,595 100.0 % Less allowance for loan losses (98,254 ) (96,485 ) Net loans $ 8,648,296 $ 8,588,110 Loan amounts are net of unearned loan fees in excess of unamortized costs of $847,000 as of June 30, 2019 and $1.4 million as of December 31, 2018 . Net loans include net discounts on acquired loans of $22.6 million and $25.7 million as of June 30, 2019 and December 31, 2018 , respectively. Purchased credit-impaired loans and purchased non-credit-impaired 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 (PCI) or purchased non-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 outstanding contractual unpaid principal balance of PCI loans, excluding acquisition accounting adjustments, was $20.2 million at June 30, 2019 and $22.0 million at December 31, 2018 . The carrying balance of PCI loans was $12.9 million at June 30, 2019 and $14.4 million at December 31, 2018 . The following table presents the changes in the accretable yield for PCI loans for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended Six Months Ended 2019 2018 2019 2018 Balance, beginning of period $ 4,778 $ 6,288 $ 5,216 $ 6,520 Accretion to interest income (456 ) (734 ) (949 ) (1,831 ) Disposals — — — 58 Reclassifications from non-accretable difference 421 555 476 1,362 Balance, end of period $ 4,743 $ 6,109 $ 4,743 $ 6,109 As of June 30, 2019 and December 31, 2018 , the non-accretable difference between the contractually required payments and cash flows expected to be collected was $6.2 million and $7.1 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, troubled debt restructurings (TDRs) that are performing under their restructured terms, and loans that are 90 days or more past due, but are still on accrual. PCI loans are considered performing within the scope of the purchased credit-impaired accounting guidance and are not included in the impaired loan tables. The following tables provide information on impaired loans, excluding PCI loans, with and without allowance reserves at June 30, 2019 and December 31, 2018 . Recorded investment includes the unpaid principal balance or the carrying amount of loans less charge-offs and net deferred loan fees (in thousands): June 30, 2019 Unpaid Principal Balance Recorded Investment Related Allowance Without Allowance (1) With Allowance (2) Commercial real estate: Owner-occupied $ 3,171 $ 2,792 $ 200 $ 20 Investment properties 2,961 1,612 699 44 Multifamily construction 1,079 605 — — One- to four-family construction 1,181 1,181 — — Land and land development: Residential 1,026 690 — — Commercial business 4,393 2,984 550 21 Agricultural business/farmland 3,903 1,359 2,320 147 One- to four-family residential 6,513 4,188 2,307 58 Consumer: Consumer secured by one- to four-family 3,269 2,983 130 5 Consumer—other 430 344 59 2 $ 27,926 $ 18,738 $ 6,265 $ 297 December 31, 2018 Unpaid Principal Balance Recorded Investment Related Allowance Without Allowance (1) With Allowance (2) Commercial real estate: Owner-occupied $ 3,193 $ 2,768 $ 200 $ 19 Investment properties 7,287 1,320 5,606 226 Multifamily real estate 1,901 1,427 — — One- to four-family construction 919 919 — — Land and land development: Residential 1,134 798 — — Commercial 44 44 — — Commercial business 4,014 2,937 391 16 Agricultural business/farmland 4,863 1,751 2,561 96 One- to four-family residential 6,724 4,314 2,358 51 Consumer: Consumer secured by one- to four-family 1,622 1,438 133 6 Consumer—other 112 49 62 2 $ 31,813 $ 17,765 $ 11,311 $ 416 (1) Includes loans without an allowance reserve that have been individually evaluated for impairment and that evaluation concluded that no reserve was needed, and $10.3 million and $9.0 million , respectively, of homogenous and small balance loans as of June 30, 2019 and December 31, 2018 , that are collectively evaluated for impairment for which a general reserve has been established. (2) 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 tables summarize our average recorded investment and interest income recognized on impaired loans by loan class for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended Three Months Ended Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial real estate: Owner-occupied $ 3,072 $ 2 $ 3,544 $ 2 Investment properties 3,283 22 7,561 75 Commercial construction 1,153 — — — One- to four-family construction 1,006 1 314 — Land and land development: Residential 690 — 1,582 10 Commercial business 3,762 6 3,206 5 Agricultural business/farmland 4,590 29 4,357 23 One- to four-family residential 6,449 57 8,226 59 Consumer: Consumer secured by one- to four-family 3,129 3 1,360 3 Consumer—other 372 1 141 1 $ 27,506 $ 121 $ 30,291 $ 178 Six Months Ended Six Months Ended Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial real estate: Owner-occupied $ 3,261 $ 4 $ 4,464 $ 5 Investment properties 5,255 98 8,767 158 Commercial construction 1,290 — — — One- to four-family construction 963 1 459 4 Land and land development: Residential 708 — 1,190 10 Commercial business 3,782 11 3,606 12 Agricultural business/farmland 4,854 56 6,733 56 One- to four-family residential 6,448 122 8,559 160 Consumer: Consumer secured by one- to four-family 2,596 8 1,375 5 Consumer—other 345 2 145 2 $ 29,502 $ 302 $ 35,298 $ 412 Troubled Debt Restructurings. Some of the Company’s loans are reported as TDRs. Loans are reported as TDRs when the bank grants one or more concessions 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. Our TDRs have generally not involved forgiveness of amounts due, but almost always include a modification of multiple factors; the most common combination includes interest rate, payment amount and maturity date. As a result of these concessions, restructured loans are impaired as the Company will not collect all amounts due, both principal and interest, in accordance with the terms of the original loan agreement. Loans identified as TDRs are accounted for in accordance with the Company's impaired loan accounting policies. The following table presents TDRs by accrual and nonaccrual status at June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Accrual Status Nonaccrual Status Total TDRs Accrual Nonaccrual Total Commercial real estate: Owner-occupied $ — $ 273 $ 273 $ 200 $ 78 $ 278 Investment properties 699 1,077 1,776 5,606 — 5,606 Commercial business 550 — 550 391 — 391 Agricultural business, including secured by farmland 2,320 — 2,320 2,561 — 2,561 One- to four-family residential 2,836 202 3,038 4,469 239 4,708 Consumer: Consumer secured by one- to four-family 130 — 130 133 — 133 Consumer—other 59 — 59 62 — 62 $ 6,594 $ 1,552 $ 8,146 $ 13,422 $ 317 $ 13,739 As of June 30, 2019 and December 31, 2018 , the Company had commitments to advance additional funds related to TDRs up to $49,000 and none , respectively. The following table presents new TDRs that occurred during the three and six months ended June 30, 2019 . No new TDRs occurred during the three and six months ended June 30, 2018 (dollars in thousands): Three months ended June 30, 2019 Six months ended June 30, 2019 Number of Contracts Pre-modification Outstanding Recorded Investment Post-modification Outstanding Recorded Investment Number of Contracts Pre- modification Outstanding Recorded Investment Post- modification Outstanding Recorded Investment Recorded Investment Commercial real estate Investment properties — $ — $ — 1 $ 1,090 $ 1,090 Commercial business 1 160 160 1 160 160 Agricultural business/farmland 1 596 596 1 596 596 Total 2 $ 756 $ 756 3 $ 1,846 $ 1,846 There were no TDRs which incurred a payment default within twelve months of the restructure date during the three and six -month periods ended June 30, 2019 and 2018 . A default on a TDR results in either a transfer to nonaccrual status or a partial charge-off, or both. 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 the six months ended June 30, 2019 . 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 which requires, however, 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 indeterminable. 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 should be 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 present the Company’s portfolio of risk-rated loans and non-risk-rated loans by grade or other characteristics as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 By class: Pass (Risk Ratings 1-5) (1) Special Mention Substandard Doubtful Loss Total Loans Commercial real estate: Owner-occupied $ 1,409,358 $ 7,880 $ 16,757 $ — $ — $ 1,433,995 Investment properties 2,107,989 — 8,317 — — 2,116,306 Multifamily real estate 401,810 — 431 — — 402,241 Commercial construction 160,616 — 12,315 — — 172,931 Multifamily construction 189,160 — — — — 189,160 One- to four-family construction 502,142 — 919 — — 503,061 Land and land development: Residential 186,490 — 690 — — 187,180 Commercial 27,434 — 36 — — 27,470 Commercial business 1,549,519 21,832 27,359 78 — 1,598,788 Agricultural business, including secured by farmland 368,172 7,109 5,524 — — 380,805 One- to four-family residential 940,607 434 3,576 — — 944,617 Consumer: Consumer secured by one- to four-family 571,458 — 4,200 — — 575,658 Consumer—other 213,777 6 555 — — 214,338 Total $ 8,628,532 $ 37,261 $ 80,679 $ 78 $ — $ 8,746,550 December 31, 2018 By class: Pass (Risk Ratings 1-5) (1) Special Mention Substandard Doubtful Loss Total Loans Commercial real estate: Owner-occupied $ 1,396,721 $ 6,963 $ 26,413 $ — $ — $ 1,430,097 Investment properties 2,122,621 — 8,438 — — 2,131,059 Multifamily real estate 368,262 — 574 — — 368,836 Commercial construction 159,167 11,816 1,427 — — 172,410 Multifamily construction 184,630 — — — — 184,630 One- to four-family construction 533,759 — 919 — — 534,678 Land and land development: Residential 187,710 — 798 — — 188,508 Commercial 27,200 — 78 — — 27,278 Commercial business 1,436,733 7,661 39,133 87 — 1,483,614 Agricultural business, including secured by farmland 392,318 4,214 8,341 — — 404,873 One- to four-family residential 969,011 499 4,106 — — 973,616 Consumer: Consumer secured by one- to four-family 564,001 — 4,978 — — 568,979 Consumer—other 215,706 9 302 — — 216,017 Total $ 8,557,839 $ 31,162 $ 95,507 $ 87 $ — $ 8,684,595 (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 June 30, 2019 and December 31, 2018 , in the commercial business category, $744.8 million and $590.9 million , respectively, of credit-scored small business loans. As loans in these pools become non-performing, they are individually risk-rated. The following tables provide additional detail on the age analysis of the Company’s past due loans as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 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 $ 1,024 $ 146 $ 2,474 $ 3,644 $ 8,413 $ 1,421,938 $ 1,433,995 $ — $ 2,991 Investment properties 148 — 1,612 1,760 3,301 2,111,245 2,116,306 — 1,612 Multifamily real estate 91 — — 91 6 402,144 402,241 — — Commercial construction — — 605 605 — 172,326 172,931 — 605 Multifamily construction — — — — — 189,160 189,160 — — One-to-four-family construction — 2,454 1,181 3,635 — 499,426 503,061 262 919 Land and land development: Residential — — 690 690 — 186,490 187,180 — 690 Commercial — — — — — 27,470 27,470 — — Commercial business 8,982 895 2,211 12,088 526 1,586,174 1,598,788 1 2,983 Agricultural business, including secured by farmland 131 30 1,359 1,520 414 378,871 380,805 — 1,359 One- to four-family residential 826 1,496 3,219 5,541 87 938,989 944,617 995 2,665 Consumer: Consumer secured by one- to four-family 1,324 346 2,233 3,903 113 571,642 575,658 66 2,917 Consumer—other 558 129 255 942 85 213,311 214,338 31 313 Total $ 13,084 $ 5,496 $ 15,839 $ 34,419 $ 12,945 $ 8,699,186 $ 8,746,550 $ 1,355 $ 17,054 December 31, 2018 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 $ 785 $ 519 $ 2,223 $ 3,527 $ 8,531 $ 1,418,039 $ 1,430,097 $ — $ 2,768 Investment properties 91 498 934 1,523 3,462 2,126,074 2,131,059 — 1,320 Multifamily real estate 317 — — 317 138 368,381 368,836 — — Commercial construction — — 1,427 1,427 — 170,983 172,410 — 1,427 Multifamily construction — — — — — 184,630 184,630 — — One-to-four-family construction 4,781 1,078 919 6,778 137 527,763 534,678 — 919 Land and land development: Residential 450 — 798 1,248 — 187,260 188,508 — 798 Commercial 34 — 44 78 — 27,200 27,278 — 44 Commercial business 3,982 1,305 1,756 7,043 1,028 1,475,543 1,483,614 1 2,936 Agricultural business, including secured by farmland 343 1,518 1,601 3,462 493 400,918 404,873 — 1,751 One-to four-family residential 5,440 1,790 1,657 8,887 101 964,628 973,616 658 1,544 Consumer: Consumer secured by one- to four-family 1,136 765 706 2,607 432 565,940 568,979 238 1,201 Consumer—other 911 385 9 1,305 91 214,621 216,017 9 40 Total $ 18,270 $ 7,858 $ 12,074 $ 38,202 $ 14,413 $ 8,631,980 $ 8,684,595 $ 906 $ 14,748 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 three and six months ended June 30, 2019 and 2018 (in thousands): For the Three Months Ended June 30, 2019 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 $ 27,091 $ 4,020 $ 23,713 $ 18,662 $ 3,596 $ 4,711 $ 7,980 $ 7,535 $ 97,308 Provision for loan losses (117 ) 324 (189 ) 1,482 222 (240 ) 828 (310 ) 2,000 Recoveries 149 — 30 215 35 230 223 — 882 Charge-offs (393 ) — — (802 ) (162 ) — (579 ) — (1,936 ) Ending balance $ 26,730 $ 4,344 $ 23,554 $ 19,557 $ 3,691 $ 4,701 $ 8,452 $ 7,225 $ 98,254 For the Six Months Ended June 30, 2019 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 $ 27,132 $ 3,818 $ 24,442 $ 19,438 $ 3,778 $ 4,714 $ 7,972 $ 5,191 $ 96,485 Provision for loan losses 252 526 (940 ) 1,273 44 (286 ) 1,097 2,034 4,000 Recoveries 170 — 52 238 35 273 333 — 1,101 Charge-offs (824 ) — — (1,392 ) (166 ) — (950 ) — (3,332 ) Ending balance $ 26,730 $ 4,344 $ 23,554 $ 19,557 $ 3,691 $ 4,701 $ 8,452 $ 7,225 $ 98,254 June 30, 2019 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance for loan losses: Individually evaluated for impairment $ 64 $ — $ — $ 21 $ 147 $ 58 $ 7 $ — $ 297 Collectively evaluated for impairment 26,666 4,344 23,554 19,513 3,487 4,643 8,445 7,225 97,877 Purchased credit-impaired loans — — — 23 57 — — — 80 Total allowance for loan losses $ 26,730 $ 4,344 $ 23,554 $ 19,557 $ 3,691 $ 4,701 $ 8,452 $ 7,225 $ 98,254 Loan balances: Individually evaluated for impairment $ 4,352 $ — $ 2,166 $ 550 $ 3,058 $ 3,582 $ 964 $ — $ 14,672 Collectively evaluated for impairment 3,534,235 402,235 1,077,636 1,597,712 377,333 940,948 788,834 — 8,718,933 Purchased credit-impaired loans 11,714 6 — 526 414 87 198 — 12,945 Total loans $ 3,550,301 $ 402,241 $ 1,079,802 $ 1,598,788 $ 380,805 $ 944,617 $ 789,996 $ — $ 8,746,550 For the Three Months Ended June 30, 2018 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 $ 23,461 $ 2,592 $ 28,766 $ 19,885 $ 2,999 $ 3,779 $ 5,514 $ 5,211 $ 92,207 Provision for loan losses 1,035 1,126 (1,743 ) (469 ) 451 (203 ) 264 1,539 2,000 Recoveries 216 — 11 100 41 356 106 — 830 Charge-offs (299 ) — — (375 ) (329 ) — (159 ) — (1,162 ) Ending balance $ 24,413 $ 3,718 $ 27,034 $ 19,141 $ 3,162 $ 3,932 $ 5,725 $ 6,750 $ 93,875 For the Six Months Ended June 30, 2018 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 $ 22,824 $ 1,633 $ 27,568 $ 18,311 $ 4,053 $ 2,055 $ 3,866 $ 8,718 $ 89,028 Provision for loan losses 320 2,085 (719 ) 1,454 (596 ) 1,247 2,177 (1,968 ) 4,000 Recoveries 1,568 — 185 270 41 646 218 — 2,928 Charge-offs (299 ) — — (894 ) (336 ) (16 ) (536 ) — (2,081 ) Ending balance $ 24,413 $ 3,718 $ 27,034 $ 19,141 $ 3,162 $ 3,932 $ 5,725 $ 6,750 $ 93,875 June 30, 2018 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance for loan losses: Individually evaluated for impairment $ 278 $ — $ — $ 13 $ 59 $ 108 $ 10 $ — $ 468 Collectively evaluated for impairment 24,135 3,718 27,034 19,095 3,043 3,824 5,715 6,750 93,314 Purchased credit-impaired loans — — — 33 60 — — — 93 Total allowance for loan losses $ 24,413 $ 3,718 $ 27,034 $ 19,141 $ 3,162 $ 3,932 $ 5,725 $ 6,750 $ 93,875 Loan balances: Individually evaluated for impairment $ 8,998 $ — $ 750 $ 369 $ 3,298 $ 4,789 $ 205 $ — $ 18,409 Collectively evaluated for impairment 3,155,917 330,220 976,435 1,310,601 333,015 835,560 706,512 — 7,648,260 Purchased credit impaired loans 12,605 164 3,255 1,454 396 121 68 — 18,063 Total loans $ 3,177,520 $ 330,384 $ 980,440 $ 1,312,424 $ 336,709 $ 840,470 $ 706,785 $ — $ 7,684,732

GOODWILL, OTHER INTANGIBLE ASSE

GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS	GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS Goodwill and Other Intangible Assets: At June 30, 2019 , intangible assets are comprised of goodwill, CDI, and favorable leasehold intangibles (LHI) acquired in business combinations. Goodwill represents the excess of the purchase consideration paid 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 at least annually for impairment. At December 31, 2018 , the Company completed its 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. 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 following table summarizes the changes in the Company’s goodwill and other intangibles for the six months ended June 30, 2019 and the year ended December 31, 2018 (in thousands): Goodwill CDI LHI Total Balance, December 31, 2017 $ 242,659 $ 22,378 $ 277 $ 265,314 Additions through acquisitions (1) 96,495 16,368 — 112,863 Amortization — (6,047 ) (52 ) (6,099 ) Balance, December 31, 2018 339,154 32,699 225 372,078 Amortization — (4,104 ) (8 ) (4,112 ) Adjustments (2) — — (217 ) (217 ) Balance, June 30, 2019 $ 339,154 $ 28,595 $ — $ 367,749 (1) The additions to goodwill and CDI in 2018 relate to the acquisition of Skagit. (2) The adjustment to LHI represents a reclassification to the right of use lease asset in connection with the implementation of Lease Topic 842. The following table presents the estimated amortization expense with respect to CDI for the periods indicated (in thousands): Estimated Amortization Remainder of 2019 $ 3,853 2020 6,888 2021 5,816 2022 4,651 2023 3,237 Thereafter 4,150 $ 28,595 Mortgage Servicing Rights: Mortgage servicing rights are reported in other assets. Mortgage servicing rights are initially recorded 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, which is recognized in servicing fee income within mortgage banking operations on the consolidated statement of operations. However, if the fair value is greater than the amortized cost, the amount above the amortized cost is not recognized in the carrying value. During the three and six months ended June 30, 2019 and 2018 , the Company did not record any impairment charges or recoveries against mortgage servicing rights. The unpaid principal balance for loans which mortgage servicing rights have been recorded totaled $2.39 billion and $2.36 billion at June 30, 2019 and December 31, 2018 , respectively. Custodial accounts maintained in connection with this servicing totaled $16.0 million and $11.1 million at June 30, 2019 and December 31, 2018 , respectively. An analysis of our mortgage servicing rights for the three and six months ended June 30, 2019 and 2018 is presented below (in thousands): Three Months Ended Six Months Ended 2019 2018 2019 2018 Balance, beginning of the period $ 14,417 $ 14,617 $ 14,638 $ 14,738 Additions—amounts capitalized 685 863 1,357 1,684 Additions—through purchase 22 30 69 45 Amortization (1) (1,126 ) (989 ) (2,066 ) (1,946 ) Balance, end of the period (2) $ 13,998 $ 14,521 $ 13,998 $ 14,521 (1) Amortization of mortgage servicing rights is recorded as a reduction of loan servicing income within mortgage banking operations and any unamortized balance is fully amortized if the loan repays in full. (2) There was no valuation allowance as of June 30, 2019 and 2018 .

REAL ESTATE OWNED, NET

REAL ESTATE OWNED, NET	6 Months Ended
	Jun. 30, 2019
Real Estate [Abstract]
REAL ESTATE OWNED, NET	REAL ESTATE OWNED, NET The following table presents the changes in REO for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended Six Months Ended 2019 2018 2019 2018 Balance, beginning of the period $ 2,611 $ 328 $ 2,611 $ 360 Additions from loan foreclosures 61 393 61 521 Proceeds from dispositions of REO (150 ) (314 ) (150 ) (314 ) Gain on sale of REO (9 ) 66 (9 ) 66 Valuation adjustments in the period — — — (160 ) Balance, end of the period $ 2,513 $ 473 $ 2,513 $ 473 REO properties are recorded at the estimated fair value of the property, less expected selling costs, establishing a new cost basis. Subsequently, REO properties are carried at the lower of the new cost basis or updated fair market values, based on updated appraisals of the underlying properties, as received. Valuation allowances on the carrying value of REO may be recognized based on updated appraisals or on management’s authorization to reduce the selling price of a property. The Company had $61,000 of foreclosed one- to four-family residential real estate properties held as REO at June 30, 2019 and none at December 31, 2018 . The recorded investment in one- to four-family residential loans in the process of foreclosure was $1.8 million at June 30, 2019 compared with $1.2 million at December 31, 2018 .

DEPOSITS

DEPOSITS	6 Months Ended
	Jun. 30, 2019
Banking and Thrift [Abstract]
DEPOSITS	DEPOSITS Deposits consisted of the following at June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Non-interest-bearing accounts $ 3,671,995 $ 3,657,817 Interest-bearing checking 1,187,035 1,191,016 Regular savings accounts 1,848,048 1,842,581 Money market accounts 1,511,119 1,465,369 Total interest-bearing transaction and saving accounts 4,546,202 4,498,966 Certificates of deposit: Certificates of deposit less than or equal to $250,000 891,312 1,143,303 Certificates of deposit greater than $250,000 179,458 176,962 Total certificates of deposit (1) 1,070,770 1,320,265 Total deposits $ 9,288,967 $ 9,477,048 Included in total deposits: Public fund transaction and savings accounts $ 223,610 $ 217,401 Public fund interest-bearing certificates 28,656 30,089 Total public deposits $ 252,266 $ 247,490 Total brokered deposits $ 138,395 $ 377,347 (1) Certificates of deposit include $384,000 and $563,000 of acquisition premiums at June 30, 2019 and December 31, 2018 , respectively. At June 30, 2019 and December 31, 2018 , the Company had certificates of deposit of $184.5 million and $180.5 million , respectively, that were equal to or greater than $250,000. Scheduled maturities and weighted average interest rates of certificate accounts at June 30, 2019 are as follows (dollars in thousands): June 30, 2019 Amount Weighted Average Rate Maturing in one year or less $ 766,901 1.14 % Maturing after one year through two years 196,538 1.65 Maturing after two years through three years 81,540 1.87 Maturing after three years through four years 12,620 1.45 Maturing after four years through five years 10,778 2.24 Maturing after five years 2,393 1.14 Total certificates of deposit $ 1,070,770 1.31 %

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
FAIR VALUE ACCOUNTING AND MEASUREMENT	FAIR VALUE OF FINANCIAL INSTRUMENTS The following table presents estimated fair values of the Company’s financial instruments as of June 30, 2019 and December 31, 2018 , whether or not measured at fair value in the Consolidated Statements of Financial Condition (dollars in thousands): June 30, 2019 December 31, 2018 Level Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Assets: Cash and cash equivalents 1 $ 187,043 $ 187,043 $ 272,196 $ 272,196 Securities—trading 3 25,741 25,741 25,896 25,896 Securities—available-for-sale 2 1,561,009 1,561,009 1,636,223 1,636,223 Securities—held-to-maturity 2 200,054 203,749 230,984 229,301 Securities—held-to-maturity 3 3,168 3,168 3,236 3,236 Loans held for sale 2 170,744 171,385 171,031 171,157 Loans receivable 3 8,746,550 8,804,689 8,684,595 8,629,450 FHLB stock 3 34,583 34,583 31,955 31,955 Bank-owned life insurance 1 178,922 178,922 177,467 177,467 Mortgage servicing rights 3 13,998 22,030 14,638 25,813 Equity securities 1 — — 352 352 Derivatives: Interest rate swaps 2 13,604 13,604 3,138 3,138 Interest rate lock and forward sales commitments 2 1,545 1,545 471 471 Liabilities: Demand, interest checking and money market accounts 2 6,370,149 6,370,149 6,314,202 6,314,202 Regular savings 2 1,848,048 1,848,048 1,842,581 1,842,581 Certificates of deposit 2 1,070,770 1,065,200 1,320,265 1,298,238 FHLB advances 2 606,000 609,464 540,189 540,189 Other borrowings 2 118,370 118,370 118,995 118,995 Junior subordinated debentures 3 113,621 113,621 114,091 114,091 Derivatives: Interest rate swaps 2 11,067 11,067 3,138 3,138 Interest rate lock and forward sales commitments 2 1,080 1,080 1,654 1,654 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 accounting standard requires the reporting entity 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. 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 certain 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 June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 Level 1 Level 2 Level 3 Total Assets: Securities—trading Corporate bonds (Trust Preferred Securities) $ — $ — $ 25,741 $ 25,741 — — 25,741 25,741 Securities—available-for-sale U.S. Government and agency obligations — 125,068 — 125,068 Municipal bonds — 110,910 — 110,910 Corporate bonds — 4,561 — 4,561 Mortgage-backed or related securities — 1,312,433 — 1,312,433 Asset-backed securities — 8,037 — 8,037 — 1,561,009 — 1,561,009 Loans held for sale — 149,691 — 149,691 Derivatives Interest rate swaps — 13,604 — 13,604 Interest rate lock and forward sales commitments — 1,545 — 1,545 $ — $ 1,725,849 $ 25,741 $ 1,751,590 Liabilities: Junior subordinated debentures, net of unamortized deferred issuance costs $ — $ — $ 113,621 $ 113,621 Derivatives Interest rate swaps — 11,067 — 11,067 Interest rate lock and forward sales commitments — 1,080 — 1,080 $ — $ 12,147 $ 113,621 $ 125,768 December 31, 2018 Level 1 Level 2 Level 3 Total Assets: Securities—trading Corporate bonds (Trust Preferred Securities) $ — $ — $ 25,896 $ 25,896 — — 25,896 25,896 Securities—available-for-sale U.S. Government and agency obligations — 149,112 — 149,112 Municipal bonds — 117,822 — 117,822 Corporate bonds — 3,495 — 3,495 Mortgage-backed securities — 1,343,861 — 1,343,861 Asset-backed securities — 21,933 — 21,933 — 1,636,223 — 1,636,223 Loans held for sale — 164,767 — 164,767 Equity securities — 352 — 352 Derivatives Interest rate swaps — 3,138 — 3,138 Interest rate lock and forward sales commitments — 471 — 471 $ — $ 1,804,951 $ 25,896 $ 1,830,847 Liabilities: Junior subordinated debentures, net of unamortized deferred issuance costs $ — $ — $ 114,091 $ 114,091 Derivatives Interest rate swaps — 3,138 — 3,138 Interest rate lock and forward sales commitments — 1,654 — 1,654 $ — $ 4,792 $ 114,091 $ 118,883 The following methods were used to estimate the fair value of each class of financial instruments above: 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 Trust Preferred Securities (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 based on discounted cash flows using as a discount rate a combination of market spreads for similar loan types added to selected index rates. 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. Junior Subordinated Debentures: The fair value of junior subordinated debentures is estimated using a discounted cash flow approach. 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 assist management in validating 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. 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 June 30, 2019 and December 31, 2018 . The factors used in the fair values 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 certain of the Company's assets and liabilities classified as Level 3 and measured at fair value on a recurring and non-recurring basis at June 30, 2019 and December 31, 2018 : Weighted Average Rate / Range Financial Instruments Valuation Techniques Unobservable Inputs June 30, 2019 December 31, 2018 Corporate bonds (TPS securities) Discounted cash flows Discount rate 6.32 % 6.81 % Junior subordinated debentures Discounted cash flows Discount rate 6.32 % 6.81 % Impaired loans Collateral Valuations Discount to appraised value 8.50% to 9.00% 0.0% to 8.50% REO Appraisals Discount to appraised value 32.00 % 69.20 % 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 and 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 June 30, 2019 , or the passage of time, will result in negative fair value adjustments. At June 30, 2019 , the discount rate utilized was based on a credit spread of 400 basis points and three-month LIBOR of 232 basis points. The following tables provide a reconciliation of the assets and liabilities measured at fair value using significant unobservable inputs (Level 3) on a recurring basis during the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended Six Months Ended June 30, 2019 June 30, 2019 Level 3 Fair Value Inputs Level 3 Fair Value Inputs TPS Securities Borrowings—Junior Subordinated Debentures TPS Securities Borrowings— Junior Subordinated Debentures Beginning balance $ 25,838 $ 113,917 $ 25,896 $ 114,091 Total gains or losses recognized Assets losses (97 ) — (155 ) — Liabilities gains — (296 ) — (470 ) Ending balance at June 30, 2019 $ 25,741 $ 113,621 $ 25,741 $ 113,621 Three Months Ended Six Months Ended June 30, 2018 June 30, 2018 Level 3 Fair Value Inputs Level 3 Fair Value Inputs TPS Securities Borrowings—Junior Subordinated Debentures TPS Securities Borrowings— Junior Subordinated Debentures Beginning balance $ 25,474 $ 112,516 $ 22,058 $ 98,707 Total gains or losses recognized Assets gains 66 — 3,482 — Liabilities losses — 258 — 14,067 Ending balance at June 30, 2018 $ 25,540 $ 112,774 $ 25,540 $ 112,774 Interest income and dividends from the TPS securities are recorded as a component of interest income. Interest expense related to the junior subordinated debentures are measured based on contractual interest rates and reported in interest expense. The change in fair market value on TPS securities has been recorded as a component of non-interest income. The change in fair value of the junior subordinated debentures, which represents changes in instrument specific credit risk, is recorded in other comprehensive income (loss). Items Measured at Fair Value on a Non-recurring Basis: The following tables present financial assets 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 as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 Level 1 Level 2 Level 3 Total Impaired loans $ — $ — $ 1,225 $ 1,225 REO — — 2,513 2,513 December 31, 2018 Level 1 Level 2 Level 3 Total Impaired loans $ — $ — $ 2,915 $ 2,915 REO — — 2,611 2,611 The following table presents the losses resulting from non-recurring fair value adjustments for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Impaired loans $ (125 ) $ (329 ) $ (425 ) $ (329 ) REO — — — (160 ) Total loss from non-recurring measurements $ (125 ) $ (329 ) $ (425 ) $ (489 ) 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. The remaining impaired loans are evaluated for reserve needs in homogenous pools within the Company’s methodology for assessing the adequacy of the allowance for loan losses. 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 lower of the estimated fair value of the real estate, less expected selling costs, or the carrying amount of the defaulted loans. 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.

INCOME TAXES AND DEFERRED TAXES

INCOME TAXES AND DEFERRED TAXES	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES AND DEFERRED TAXES	INCOME TAXES AND DEFERRED 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 provide 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 June 30, 2019 , the Company had an insignificant amount of unrecognized tax benefits for uncertain tax positions, none of which 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 the income tax expense. The Company files consolidated income tax returns in the U.S. federal jurisdiction and in the Oregon, California, Utah, Idaho and Montana state jurisdictions. 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 June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Tax credit investments $ 21,359 $ 17,360 Unfunded commitments—tax credit investments 15,700 12,726 The following table presents other information related to the Company's tax credit investments for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended Six Months Ended 2019 2018 2019 2018 Tax credits and other tax benefits recognized $ 494 $ 364 $ 988 $ 728 Tax credit amortization expense included in provision for income taxes 405 288 810 575

CALCULATION OF WEIGHTED AVERAGE

CALCULATION OF WEIGHTED AVERAGE SHARES OUTSTANDING FOR EARNINGS PER SHARE (EPS)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
CALCULATION OF WEIGHTED AVERAGE SHARES OUTSTANDING FOR EARNINGS PER SHARE (EPS)	CALCULATION OF WEIGHTED AVERAGE SHARES OUTSTANDING FOR EARNINGS PER SHARE (EPS) The following table reconciles basic to diluted weighted average shares outstanding used to calculate earnings per share data for the three and six months ended June 30, 2019 and 2018 (in thousands, except shares and per share data): Three Months Ended Six Months Ended 2019 2018 2019 2018 Net income $ 39,700 $ 32,424 $ 73,046 $ 61,214 Basic weighted average shares outstanding 34,831,047 32,250,514 34,940,106 32,323,635 Plus unvested restricted stock 51,312 81,095 88,775 98,652 Diluted weighted shares outstanding 34,882,359 32,331,609 35,028,881 32,422,287 Earnings per common share Basic $ 1.14 $ 1.01 $ 2.09 $ 1.89 Diluted $ 1.14 $ 1.00 $ 2.09 $ 1.89

STOCK-BASED COMPENSATION PLANS

STOCK-BASED COMPENSATION PLANS	6 Months Ended
	Jun. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION PLANS AND STOCK OPTIONS	STOCK-BASED COMPENSATION PLANS The Company operates the following stock-based compensation plans as approved by its shareholders: • 2012 Restricted Stock and Incentive Bonus Plan (2012 Restricted Stock Plan). • 2014 Omnibus Incentive Plan (the 2014 Plan). • 2018 Omnibus Incentive Plan (the 2018 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 and restricted stock unit grants. 2012 Restricted Stock and Incentive Bonus Plan Under the 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, or market-based conditions. As of June 30, 2019 , the Company had granted 269,863 shares of restricted stock from the 2012 Restricted Stock Plan (as amended and restated), of which 261,966 shares had vested and 7,897 shares remain unvested. 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 reserved 900,000 shares of its common stock for issuance under the 2014 Plan in connection with the exercise of awards. As of June 30, 2019 , 316,281 restricted stock shares and 384,117 restricted stock units have been granted under the 2014 Plan of which 281,760 restricted stock shares and 52,371 restricted stock units have vested. 2018 Omnibus Incentive Plan The 2018 Plan was approved by shareholders on April 24, 2018. The 2018 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 reserved 900,000 shares of common stock for issuance under the 2018 Plan in connection with the exercise of awards. As of June 30, 2019 , no shares or units have been granted under the 2018 Plan. The expense associated with all restricted stock grants (including restricted stock shares and restricted stock units) was $2.2 million and $3.5 million for the three and six month periods ended June 30, 2019 and was $1.9 million and $3.3 million for the three and six month periods ended June 30, 2018 , respectively. Unrecognized compensation expense for these awards as of June 30, 2019 was $15.9 million and will be amortized over the next 36 months .

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES 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 our customers. These financial instruments include commitments to extend credit, commitments related to standby letters of credit, commitments to originate loans, commitments to sell loans, commitments to buy and 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 June 30, 2019 December 31, 2018 Commitments to extend credit $ 2,934,838 $ 2,837,981 Standby letters of credit and financial guarantees 15,529 17,784 Commitments to originate loans 61,037 32,145 Risk participation agreement 41,057 24,091 Derivatives also included in Note 14: Commitments to originate loans held for sale 110,648 31,728 Commitments to sell loans secured by one- to four-family residential properties 46,726 18,328 Commitments to sell securities related to mortgage banking activities 225,703 144,250 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. The type of 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 $2.6 million at both June 30, 2019 and December 31, 2018 . 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 AmericanWest, 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 an 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 Company 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 required a lock extension. The cost of a lock extension at times was borne by the customer and at times by the Company. These lock extension costs have not had a material impact to our operations. 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 the three and six months ended June 30, 2019 or June 30, 2018 . 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. 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 June 30, 2019 . 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 Banks 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

DERIVATIVES AND HEDGING	6 Months Ended
	Jun. 30, 2019
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 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. Banner Bank discontinued originating interest rate swaps under this program in 2008. As of June 30, 2019 and December 31, 2018 , 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 June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 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 $ 3,773 $ 279 $ 3,973 $ 270 $ 3,773 $ 279 $ 3,973 $ 270 (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 locks in a fixed rate and the Bank receives a variable 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 one- to four-family and multifamily 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 one- to four-family loans that are intended to be sold and for closed one- to four-family and multifamily mortgage loans held for sale that are awaiting sale and delivery into the secondary market. The Company attempts to economically hedge the risk of changing interest rates associated with these mortgage loan commitments by entering into forward sales contracts to sell one- to four-family and multifamily mortgage loans or mortgage-backed securities to broker/dealers as specific prices and dates. As of June 30, 2019 and December 31, 2018 , 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 June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 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 $ 287,416 $ 13,325 $ 272,374 $ 2,868 $ 287,416 $ 10,788 $ 272,374 $ 2,868 Mortgage loan commitments 88,810 1,373 20,229 273 42,890 45 17,763 187 Forward sales contracts 46,726 172 18,328 198 225,703 1,035 144,250 1,467 $ 422,952 $ 14,870 $ 310,931 $ 3,339 $ 556,009 $ 11,868 $ 434,387 $ 4,522 (1) Included in Other assets on the Consolidated Statements of Financial Condition, with the exception of certain interest swaps and mortgage loan commitments (with a fair value of $406,000 at June 30, 2019 and $282,000 at December 31, 2018 ), which are included in Loans receivable. (2) Included in Other liabilities on the Consolidated Statements of Financial Condition. Gains (losses) recognized in income on derivatives not designated in hedge relationships for the three and six months ended June 30, 2019 and 2018 were as follows (in thousands): Location on Consolidated Statements of Operations Three Months Ended Six Months Ended 2019 2018 2019 2018 Mortgage loan commitments Mortgage banking operations $ 1,093 $ 96 $ 1,100 $ 164 Forward sales contracts Mortgage banking operations (392 ) (73 ) (242 ) 268 $ 701 $ 23 $ 858 $ 432 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 June 30, 2019 or December 31, 2018 , it could have been required to settle its obligations under the agreements at the termination value. As of June 30, 2019 and December 31, 2018 , the termination value of derivatives in a net liability position related to these agreements was $13.6 million and $1.3 million , respectively. The Company generally posts collateral against derivative liabilities in the form of cash, government agency-issued bonds, mortgage-backed securities, or commercial mortgage-backed securities. Collateral posted against derivative liabilities was $20.7 million and $13.6 million as of June 30, 2019 and December 31, 2018 , respectively. Derivative assets and liabilities are recorded at fair value on the balance sheet. 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 tables present additional information related to the Company's derivative contracts, by type of financial instrument, as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 Gross Amounts of Financial Instruments Not Offset in the Consolidated Statements 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 $ 13,621 $ (17 ) $ 13,604 $ — $ — $ 13,604 $ 13,621 $ (17 ) $ 13,604 $ — $ — $ 13,604 Derivative liabilities Interest rate swaps $ 13,621 $ (2,554 ) $ 11,067 $ — $ (10,919 ) $ 148 $ 13,621 $ (2,554 ) $ 11,067 $ — $ (10,919 ) $ 148 December 31, 2018 Gross Amounts of Financial Instruments Not Offset in the Consolidated Statements 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 $ 5,038 $ (1,900 ) $ 3,138 $ — $ — $ 3,138 $ 5,038 $ (1,900 ) $ 3,138 $ — $ — $ 3,138 Derivative liabilities Interest rate swaps $ 5,038 $ (1,900 ) $ 3,138 $ — $ (1,320 ) $ 1,818 $ 5,038 $ (1,900 ) $ 3,138 $ — $ (1,320 ) $ 1,818

REVENUE FROM CONTRACTS WITH CUS

REVENUE FROM CONTRACTS WITH CUSTOMERS	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	REVENUE FROM CONTRACTS WITH CUSTOMERS Disaggregation of Revenue: Deposit fees and other service charges for the three and six months ended June 30, 2019 and 2018 are summarized as follows (in thousands): Three Months Ended Six Months Ended 2019 2018 2019 2018 Deposit service charges $ 4,829 $ 4,528 $ 9,416 $ 8,848 Debit and credit card interchange fees 9,272 7,872 17,203 15,191 Debit and credit card expense (1,949 ) (1,933 ) (4,398 ) (3,903 ) Merchant services income 3,345 2,513 6,201 4,774 Merchant services expense (2,661 ) (1,924 ) (4,981 ) (3,729 ) Other service charges 1,210 929 3,223 2,100 Total deposit fees and other service charges $ 14,046 $ 11,985 $ 26,664 $ 23,281 Deposit fees and other service charges Deposit fees and other service charges include transaction and non-transaction based deposit fees. Transaction based fees on deposit accounts are charged to deposit customers for specific services provided to the customer. These fees include such items as wire fees, official check fees, and overdraft fees. These are contract specific to each individual transaction and do not extend beyond the individual transaction. The performance obligation is completed and the fees are recognized at the time the specific transactional service is provided to the customer. Non-transactional deposit fees are typically monthly account maintenance fees charged on deposit accounts. These are day-to-day contracts that can be canceled by either party without notice. The performance obligation is satisfied and the fees are recognized on a monthly basis after the service period is completed. Debit and credit card interchange income and expenses Debit and credit card interchange income represent fees earned when a debit or credit card issued by the Banks is used to purchase goods or services at a merchant. The merchant's bank pays the Banks a default interchange rate set by MasterCard on a transaction by transaction basis. The merchant acquiring bank can stop accepting the Banks’ cards at any time and the Banks can stop further use of cards issued by them at any time. The performance obligation is satisfied and the fees are earned when the cost of the transaction is charged to the Banks cardholders’ card. Direct expenses associated with the credit and debit card are recorded as a net reduction against the interchange income. Merchant services income Merchant services income represents fees earned by the Banks for card payment services provided to its merchant customers. The Banks have a contract with a third party to provide card payment services to the Banks’ merchants that contract for those services. The third party provider has contracts with the Banks’ merchants to provide the card payment services. The Banks do not have a direct contractual relationship with its merchants for these services. The Banks set the rates for the services provided by the third party. The third party provider passes the payments made by the Banks’ merchants through to the Banks. The Banks, in turn, pay the third party provider for the services it provides to the Banks’ merchants. These payments to the third party provider are recorded as expenses as a net reduction against fee income. In addition, a portion of the payment received by the Banks represents interchange fees which are passed through to the card issuing bank. Income is primarily earned based on the dollar volume and number of transactions processed. The performance obligation is satisfied and the related fee is earned when each payment is accepted by the processing network.

LEASES

LEASES	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
LEASES	LEASES The Company leases 106 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. The Company adopted the requirements of Topic 842 effective January 1, 2019, which required the Company to record a right-of-use lease asset and a lease liability for leases with an initial term of more than 12 months for leases that existed as of January 1, 2019. The periods prior to the date of adoption are accounted for under Lease Topic 840; therefore, the following disclosures include only the periods for which Topic 842 was effective. Lease Position as of June 30, 2019 The table below presents the lease right-of-use assets and lease liabilities recorded on the balance sheet at June 30, 2019 (dollars in thousands): Classification on the Balance Sheet June 30, 2019 Assets Operating right-of-use lease assets Other assets $ 54,515 Liabilities Operating lease liabilities Accrued expenses and other liabilities $ 57,638 Weighted-average remaining lease term Operating leases 5.8 years Weighted-average discount rate Operating leases 4.24 % Lease Costs The table below presents certain information related to the lease costs for operating leases for the three and six months ended June 30, 2019 (in thousands): Three Months Ended Six Months Ended 2019 2019 Operating lease cost (1) $ 3,858 $ 7,832 Short-term lease cost (1) 99 222 Variable lease cost (1) 567 1,128 Less sublease income (1) (231 ) (468 ) Total lease cost $ 4,293 $ 8,714 (1) Lease expenses and sublease income are classified within occupancy and equipment expense on the Consolidated Statements of Operations. Supplemental Cash Flow Information Operating cash flows paid for operating lease amounts included in the measurement of lease liabilities were $3.8 million and $7.7 million for the three and six months ended June 30, 2019 , respectively. During the three and six months ended June 30, 2019 , the Company recorded $2.9 million and $64.1 million , respectively, of right-of-use lease assets in exchange for operating lease liabilities. Undiscounted Cash Flows The table below reconciles the undiscounted cash flows for each of the first five years beginning with 2019 and the total of the remaining years to the operating lease liabilities recorded on the Consolidated Statements of Financial Position (in thousands): Operating Leases Remainder of 2019 $ 7,514 2020 14,330 2021 12,611 2022 9,083 2023 6,011 Thereafter 15,659 Total minimum lease payments 65,208 Less: amount of lease payments representing interest (7,570 ) Lease obligations $ 57,638 As of June 30, 2019 , the Company had $2.8 million of undiscounted lease payments under an operating lease that had not yet commenced. This lease will commence later in 2019 with a lease term of 20 years.

SUBSEQUENT EVENT (Notes)

SUBSEQUENT EVENT (Notes)	6 Months Ended
	Jun. 30, 2019
Subsequent Events [Abstract]
Subsequent Events [Text Block]	SUBSEQUENT EVENT On July 24, 2019 , the Company announced the execution of a definitive agreement to purchase AltaPacific, the holding company for AltaPacific Bank, a California state-chartered commercial bank. Subject to the terms and conditions of the merger agreement, the transaction provides for the AltaPacific shareholders to receive consideration of 0.2712 shares of Banner common stock in exchange for each share of AltaPacific common stock, subject to potential adjustment as provided in the merger agreement. Based on the closing price of $54.19 per share of Banner common stock on July 23, 2019, the merger consideration would have an aggregate value of approximately $87.4 million . Completion of the transaction is subject to customary conditions, including approval of the merger agreement by AltaPacific shareholders, regulatory approvals and other customary closing conditions and is expected to close late in the fourth quarter of 2019. Upon closing of the transaction AltaPacific will be merged into Banner and AltaPacific Bank will be merged into Banner Bank. At June 30, 2019, AltaPacific had assets of $436 million , loans of $339 million , and deposits of $307 million with five banking locations in Southern California and one banking location in Northern California.

BASIS OF PRESENTATION AND SIG_2

BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting	The accompanying unaudited condensed consolidated financial statements include the accounts of Banner Corporation (the Company or Banner), a bank holding company incorporated in the State of Washington and its wholly-owned subsidiaries, Banner Bank and Islanders Bank (the Banks). These unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP) for interim financial information and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X as promulgated by the Securities and Exchange Commission (SEC). In preparing these financial statements, the Company has evaluated events and transactions subsequent to June 30, 2019 for potential recognition or disclosure. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of the financial position and results of operations for the periods presented have been included. Certain information and disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations of the SEC and the accounting standards for interim financial statements. Certain reclassifications have been made to the 2018 Consolidated Financial Statements and/or schedules to conform to the 2019 presentation. These reclassifications may have affected certain ratios for the prior periods. The effect of these reclassifications is considered immaterial. All significant intercompany transactions and balances have been eliminated. 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 significant 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 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 of assets acquired and liabilities assumed in business combinations and subsequent recognition of related income and expense, and (vii) the valuation or recognition of deferred tax assets and liabilities. These policies and judgments, estimates and assumptions are described in greater detail in subsequent notes to the Consolidated Financial Statements and Management’s Discussion and Analysis of Financial Condition and Results of Operations (Critical Accounting Policies) in our Annual Report on Form 10-K for the year ended December 31, 2018 filed with the SEC (2018 Form 10-K). There have been no significant changes in our application of these accounting policies during the first six months of 2019 , except as described in Note 2. On July 25, 2019, Banner and AltaPacific Bancorp, Inc. (“AltaPacific”), the holding company for AltaPacific Bank, a California state-chartered commercial bank, announced that they have entered into a definitive merger agreement pursuant to which Banner will acquire AltaPacific in an all-stock transaction, subject to the terms and conditions set forth therein. Under the merger agreement, AltaPacific will merge with and into Banner, and immediately thereafter AltaPacific Bank will merge with and into Banner Bank. The combined company will have approximately $12.2 billion in assets. See Note 17 for additional information on the transaction. The information included in this Form 10-Q should be read in conjunction with our 2018 Form 10-K. Interim results are not necessarily indicative of results for a full year or any other interim period.

SECURITIES (Tables)

SECURITIES (Tables)	6 Months Ended
	Jun. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Schedule of Securities	The amortized cost, gross unrealized gains and losses and estimated fair value of securities at June 30, 2019 and December 31, 2018 are summarized as follows (in thousands): June 30, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Trading: Corporate bonds $ 27,203 $ 25,741 $ 27,203 $ 25,741 Available-for-Sale: U.S. Government and agency obligations $ 125,597 $ 437 $ (966 ) $ 125,068 Municipal bonds 106,379 4,549 (18 ) 110,910 Corporate bonds 4,557 12 (8 ) 4,561 Mortgage-backed or related securities 1,291,166 22,751 (1,484 ) 1,312,433 Asset-backed securities 8,076 2 (41 ) 8,037 $ 1,535,775 $ 27,751 $ (2,517 ) $ 1,561,009 Held-to-Maturity: U.S. Government and agency obligations $ 388 $ 6 $ — $ 394 Municipal bonds 148,580 3,538 (629 ) 151,489 Corporate bonds 3,668 — (12 ) 3,656 Mortgage-backed or related securities 50,586 821 (29 ) 51,378 $ 203,222 $ 4,365 $ (670 ) $ 206,917 December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Trading: Corporate bonds $ 27,203 $ 25,896 $ 27,203 $ 25,896 Available-for-Sale: U.S. Government and agency obligations $ 151,012 $ 149 $ (2,049 ) $ 149,112 Municipal bonds 116,548 1,806 (532 ) 117,822 Corporate bonds 3,556 — (61 ) 3,495 Mortgage-backed or related securities 1,355,258 5,210 (16,607 ) 1,343,861 Asset-backed securities 22,047 6 (120 ) 21,933 $ 1,648,421 $ 7,171 $ (19,369 ) $ 1,636,223 Held-to-Maturity: U.S. Government and agency obligations $ 1,006 $ 14 $ (1 ) $ 1,019 Municipal bonds 176,663 1,727 (2,578 ) 175,812 Corporate bonds 3,736 — (13 ) 3,723 Mortgage-backed or related securities 52,815 66 (898 ) 51,983 $ 234,220 $ 1,807 $ (3,490 ) $ 232,537
Schedule of Securities with Continuous Loss Position	At June 30, 2019 and December 31, 2018 , 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 were as follows (in thousands): June 30, 2019 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 $ — $ — $ 71,611 $ (966 ) $ 71,611 $ (966 ) Municipal bonds 493 (3 ) 3,230 (15 ) 3,723 (18 ) Corporate bonds 352 (1 ) 1,798 (7 ) 2,150 (8 ) Mortgage-backed or related securities 73,934 (483 ) 207,659 (1,001 ) 281,593 (1,484 ) Asset-backed securities 7,314 (40 ) 229 (1 ) 7,543 (41 ) $ 82,093 $ (527 ) $ 284,527 $ (1,990 ) $ 366,620 $ (2,517 ) Held-to-Maturity Municipal bonds $ — $ — $ 23,378 $ (629 ) $ 23,378 $ (629 ) Corporate bonds — — 488 (12 ) 488 (12 ) Mortgage-backed or related securities 2,211 (1 ) 6,128 (28 ) 8,339 (29 ) $ 2,211 $ (1 ) $ 29,994 $ (669 ) $ 32,205 $ (670 ) December 31, 2018 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 $ 75,885 $ (1,240 ) $ 50,508 $ (809 ) $ 126,393 $ (2,049 ) Municipal bonds 6,422 (54 ) 27,231 (478 ) 33,653 (532 ) Corporate bonds 3,199 (56 ) 295 (5 ) 3,494 (61 ) Mortgage-backed or related securities 316,074 (2,939 ) 571,989 (13,668 ) 888,063 (16,607 ) Asset-backed securities 10,582 (24 ) 9,913 (96 ) 20,495 (120 ) $ 412,162 $ (4,313 ) $ 659,936 $ (15,056 ) $ 1,072,098 $ (19,369 ) Held-to-Maturity U.S. Government and agency obligations $ 145 $ (1 ) $ — $ — $ 145 $ (1 ) Municipal bonds 29,898 (274 ) 44,637 (2,304 ) 74,535 (2,578 ) Corporate bonds — — 487 (13 ) 487 (13 ) Mortgage-backed or related securities 10,761 (220 ) 30,035 (678 ) 40,796 (898 ) $ 40,804 $ (495 ) $ 75,159 $ (2,995 ) $ 115,963 $ (3,490 )
Schedule of Securities by Contractual Maturity Date	The amortized cost and estimated fair value of securities at June 30, 2019 , 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. June 30, 2019 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 $ — $ — $ 2,554 $ 2,556 $ 4,602 $ 4,604 Maturing after one year through five years — — 57,247 58,238 63,805 64,663 Maturing after five years through ten years — — 393,053 404,449 43,943 45,457 Maturing after ten years through twenty years 27,203 25,741 178,802 183,689 58,805 60,672 Maturing after twenty years — — 904,119 912,077 32,067 31,521 $ 27,203 $ 25,741 $ 1,535,775 $ 1,561,009 $ 203,222 $ 206,917
Schedule of Pledged Securities	The following table presents, as of June 30, 2019 , investment securities which were pledged to secure borrowings, public deposits or other obligations as permitted or required by law (in thousands): June 30, 2019 Carrying Value Amortized Cost Fair Value Purpose or beneficiary: State and local governments public deposits $ 136,556 $ 136,217 $ 139,723 Interest rate swap counterparties 15,560 15,494 15,741 Repurchase agreements 144,625 142,411 144,625 Other 2,721 2,721 2,698 Total pledged securities $ 299,462 $ 296,843 $ 302,787

LOANS RECEIVABLE AND THE ALLO_2

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Tables)	6 Months Ended
	Jun. 30, 2019
Receivables [Abstract]
Schedule of Loans Receivable, Including Loans Held for Sale	Loans receivable at June 30, 2019 and December 31, 2018 are summarized as follows (dollars in thousands): June 30, 2019 December 31, 2018 Amount Percent of Total Amount Percent of Total Commercial real estate: Owner-occupied $ 1,433,995 16.4 % $ 1,430,097 16.4 % Investment properties 2,116,306 24.2 2,131,059 24.5 Multifamily real estate 402,241 4.6 368,836 4.2 Commercial construction 172,931 2.0 172,410 2.0 Multifamily construction 189,160 2.2 184,630 2.1 One- to four-family construction 503,061 5.7 534,678 6.2 Land and land development: Residential 187,180 2.1 188,508 2.2 Commercial 27,470 0.3 27,278 0.3 Commercial business 1,598,788 18.3 1,483,614 17.1 Agricultural business, including secured by farmland 380,805 4.3 404,873 4.7 One- to four-family residential 944,617 10.8 973,616 11.2 Consumer: Consumer secured by one- to four-family 575,658 6.6 568,979 6.6 Consumer—other 214,338 2.5 216,017 2.5 Total loans 8,746,550 100.0 % 8,684,595 100.0 % Less allowance for loan losses (98,254 ) (96,485 ) Net loans $ 8,648,296 $ 8,588,110 Loan amounts are net of unearned loan fees in excess of unamortized costs of $847,000 as of June 30, 2019 and $1.4 million as of December 31, 2018 . Net loans include net discounts on acquired loans of $22.6 million and $25.7 million as of June 30, 2019 and December 31, 2018 , 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 three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended Six Months Ended 2019 2018 2019 2018 Balance, beginning of period $ 4,778 $ 6,288 $ 5,216 $ 6,520 Accretion to interest income (456 ) (734 ) (949 ) (1,831 ) Disposals — — — 58 Reclassifications from non-accretable difference 421 555 476 1,362 Balance, end of period $ 4,743 $ 6,109 $ 4,743 $ 6,109
Impaired loans excluding purchased credit impaired loans [Table Text Block]	The following tables provide information on impaired loans, excluding PCI loans, with and without allowance reserves at June 30, 2019 and December 31, 2018 . Recorded investment includes the unpaid principal balance or the carrying amount of loans less charge-offs and net deferred loan fees (in thousands): June 30, 2019 Unpaid Principal Balance Recorded Investment Related Allowance Without Allowance (1) With Allowance (2) Commercial real estate: Owner-occupied $ 3,171 $ 2,792 $ 200 $ 20 Investment properties 2,961 1,612 699 44 Multifamily construction 1,079 605 — — One- to four-family construction 1,181 1,181 — — Land and land development: Residential 1,026 690 — — Commercial business 4,393 2,984 550 21 Agricultural business/farmland 3,903 1,359 2,320 147 One- to four-family residential 6,513 4,188 2,307 58 Consumer: Consumer secured by one- to four-family 3,269 2,983 130 5 Consumer—other 430 344 59 2 $ 27,926 $ 18,738 $ 6,265 $ 297 December 31, 2018 Unpaid Principal Balance Recorded Investment Related Allowance Without Allowance (1) With Allowance (2) Commercial real estate: Owner-occupied $ 3,193 $ 2,768 $ 200 $ 19 Investment properties 7,287 1,320 5,606 226 Multifamily real estate 1,901 1,427 — — One- to four-family construction 919 919 — — Land and land development: Residential 1,134 798 — — Commercial 44 44 — — Commercial business 4,014 2,937 391 16 Agricultural business/farmland 4,863 1,751 2,561 96 One- to four-family residential 6,724 4,314 2,358 51 Consumer: Consumer secured by one- to four-family 1,622 1,438 133 6 Consumer—other 112 49 62 2 $ 31,813 $ 17,765 $ 11,311 $ 416 (1) Includes loans without an allowance reserve that have been individually evaluated for impairment and that evaluation concluded that no reserve was needed, and $10.3 million and $9.0 million , respectively, of homogenous and small balance loans as of June 30, 2019 and December 31, 2018 , that are collectively evaluated for impairment for which a general reserve has been established. (2) 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.
Schedule of Impaired Loans With and Without Specific Reserves	The following tables summarize our average recorded investment and interest income recognized on impaired loans by loan class for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended Three Months Ended Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial real estate: Owner-occupied $ 3,072 $ 2 $ 3,544 $ 2 Investment properties 3,283 22 7,561 75 Commercial construction 1,153 — — — One- to four-family construction 1,006 1 314 — Land and land development: Residential 690 — 1,582 10 Commercial business 3,762 6 3,206 5 Agricultural business/farmland 4,590 29 4,357 23 One- to four-family residential 6,449 57 8,226 59 Consumer: Consumer secured by one- to four-family 3,129 3 1,360 3 Consumer—other 372 1 141 1 $ 27,506 $ 121 $ 30,291 $ 178 Six Months Ended Six Months Ended Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial real estate: Owner-occupied $ 3,261 $ 4 $ 4,464 $ 5 Investment properties 5,255 98 8,767 158 Commercial construction 1,290 — — — One- to four-family construction 963 1 459 4 Land and land development: Residential 708 — 1,190 10 Commercial business 3,782 11 3,606 12 Agricultural business/farmland 4,854 56 6,733 56 One- to four-family residential 6,448 122 8,559 160 Consumer: Consumer secured by one- to four-family 2,596 8 1,375 5 Consumer—other 345 2 145 2 $ 29,502 $ 302 $ 35,298 $ 412
Schedule of Troubled Debt Restructurings	The following table presents TDRs by accrual and nonaccrual status at June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Accrual Status Nonaccrual Status Total TDRs Accrual Nonaccrual Total Commercial real estate: Owner-occupied $ — $ 273 $ 273 $ 200 $ 78 $ 278 Investment properties 699 1,077 1,776 5,606 — 5,606 Commercial business 550 — 550 391 — 391 Agricultural business, including secured by farmland 2,320 — 2,320 2,561 — 2,561 One- to four-family residential 2,836 202 3,038 4,469 239 4,708 Consumer: Consumer secured by one- to four-family 130 — 130 133 — 133 Consumer—other 59 — 59 62 — 62 $ 6,594 $ 1,552 $ 8,146 $ 13,422 $ 317 $ 13,739 As of June 30, 2019 and December 31, 2018 , the Company had commitments to advance additional funds related to TDRs up to $49,000 and none , respectively.
Schedule of Risk-Rated Loans and Non-Risk Rated Loans by Grade and Other Characteristics	The following tables present the Company’s portfolio of risk-rated loans and non-risk-rated loans by grade or other characteristics as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 By class: Pass (Risk Ratings 1-5) (1) Special Mention Substandard Doubtful Loss Total Loans Commercial real estate: Owner-occupied $ 1,409,358 $ 7,880 $ 16,757 $ — $ — $ 1,433,995 Investment properties 2,107,989 — 8,317 — — 2,116,306 Multifamily real estate 401,810 — 431 — — 402,241 Commercial construction 160,616 — 12,315 — — 172,931 Multifamily construction 189,160 — — — — 189,160 One- to four-family construction 502,142 — 919 — — 503,061 Land and land development: Residential 186,490 — 690 — — 187,180 Commercial 27,434 — 36 — — 27,470 Commercial business 1,549,519 21,832 27,359 78 — 1,598,788 Agricultural business, including secured by farmland 368,172 7,109 5,524 — — 380,805 One- to four-family residential 940,607 434 3,576 — — 944,617 Consumer: Consumer secured by one- to four-family 571,458 — 4,200 — — 575,658 Consumer—other 213,777 6 555 — — 214,338 Total $ 8,628,532 $ 37,261 $ 80,679 $ 78 $ — $ 8,746,550 December 31, 2018 By class: Pass (Risk Ratings 1-5) (1) Special Mention Substandard Doubtful Loss Total Loans Commercial real estate: Owner-occupied $ 1,396,721 $ 6,963 $ 26,413 $ — $ — $ 1,430,097 Investment properties 2,122,621 — 8,438 — — 2,131,059 Multifamily real estate 368,262 — 574 — — 368,836 Commercial construction 159,167 11,816 1,427 — — 172,410 Multifamily construction 184,630 — — — — 184,630 One- to four-family construction 533,759 — 919 — — 534,678 Land and land development: Residential 187,710 — 798 — — 188,508 Commercial 27,200 — 78 — — 27,278 Commercial business 1,436,733 7,661 39,133 87 — 1,483,614 Agricultural business, including secured by farmland 392,318 4,214 8,341 — — 404,873 One- to four-family residential 969,011 499 4,106 — — 973,616 Consumer: Consumer secured by one- to four-family 564,001 — 4,978 — — 568,979 Consumer—other 215,706 9 302 — — 216,017 Total $ 8,557,839 $ 31,162 $ 95,507 $ 87 $ — $ 8,684,595 (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 June 30, 2019 and December 31, 2018 , in the commercial business category, $744.8 million and $590.9 million , respectively, of credit-scored small business loans. As loans in these pools become non-performing, they are individually risk-rated.
Schedule of Age Analysis of the Company's Past Due Loans	The following tables provide additional detail on the age analysis of the Company’s past due loans as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 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 $ 1,024 $ 146 $ 2,474 $ 3,644 $ 8,413 $ 1,421,938 $ 1,433,995 $ — $ 2,991 Investment properties 148 — 1,612 1,760 3,301 2,111,245 2,116,306 — 1,612 Multifamily real estate 91 — — 91 6 402,144 402,241 — — Commercial construction — — 605 605 — 172,326 172,931 — 605 Multifamily construction — — — — — 189,160 189,160 — — One-to-four-family construction — 2,454 1,181 3,635 — 499,426 503,061 262 919 Land and land development: Residential — — 690 690 — 186,490 187,180 — 690 Commercial — — — — — 27,470 27,470 — — Commercial business 8,982 895 2,211 12,088 526 1,586,174 1,598,788 1 2,983 Agricultural business, including secured by farmland 131 30 1,359 1,520 414 378,871 380,805 — 1,359 One- to four-family residential 826 1,496 3,219 5,541 87 938,989 944,617 995 2,665 Consumer: Consumer secured by one- to four-family 1,324 346 2,233 3,903 113 571,642 575,658 66 2,917 Consumer—other 558 129 255 942 85 213,311 214,338 31 313 Total $ 13,084 $ 5,496 $ 15,839 $ 34,419 $ 12,945 $ 8,699,186 $ 8,746,550 $ 1,355 $ 17,054 December 31, 2018 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 $ 785 $ 519 $ 2,223 $ 3,527 $ 8,531 $ 1,418,039 $ 1,430,097 $ — $ 2,768 Investment properties 91 498 934 1,523 3,462 2,126,074 2,131,059 — 1,320 Multifamily real estate 317 — — 317 138 368,381 368,836 — — Commercial construction — — 1,427 1,427 — 170,983 172,410 — 1,427 Multifamily construction — — — — — 184,630 184,630 — — One-to-four-family construction 4,781 1,078 919 6,778 137 527,763 534,678 — 919 Land and land development: Residential 450 — 798 1,248 — 187,260 188,508 — 798 Commercial 34 — 44 78 — 27,200 27,278 — 44 Commercial business 3,982 1,305 1,756 7,043 1,028 1,475,543 1,483,614 1 2,936 Agricultural business, including secured by farmland 343 1,518 1,601 3,462 493 400,918 404,873 — 1,751 One-to four-family residential 5,440 1,790 1,657 8,887 101 964,628 973,616 658 1,544 Consumer: Consumer secured by one- to four-family 1,136 765 706 2,607 432 565,940 568,979 238 1,201 Consumer—other 911 385 9 1,305 91 214,621 216,017 9 40 Total $ 18,270 $ 7,858 $ 12,074 $ 38,202 $ 14,413 $ 8,631,980 $ 8,684,595 $ 906 $ 14,748
Allowance for Credit Losses on Financing Receivables	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 three and six months ended June 30, 2019 and 2018 (in thousands): For the Three Months Ended June 30, 2019 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 $ 27,091 $ 4,020 $ 23,713 $ 18,662 $ 3,596 $ 4,711 $ 7,980 $ 7,535 $ 97,308 Provision for loan losses (117 ) 324 (189 ) 1,482 222 (240 ) 828 (310 ) 2,000 Recoveries 149 — 30 215 35 230 223 — 882 Charge-offs (393 ) — — (802 ) (162 ) — (579 ) — (1,936 ) Ending balance $ 26,730 $ 4,344 $ 23,554 $ 19,557 $ 3,691 $ 4,701 $ 8,452 $ 7,225 $ 98,254 For the Six Months Ended June 30, 2019 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 $ 27,132 $ 3,818 $ 24,442 $ 19,438 $ 3,778 $ 4,714 $ 7,972 $ 5,191 $ 96,485 Provision for loan losses 252 526 (940 ) 1,273 44 (286 ) 1,097 2,034 4,000 Recoveries 170 — 52 238 35 273 333 — 1,101 Charge-offs (824 ) — — (1,392 ) (166 ) — (950 ) — (3,332 ) Ending balance $ 26,730 $ 4,344 $ 23,554 $ 19,557 $ 3,691 $ 4,701 $ 8,452 $ 7,225 $ 98,254 June 30, 2019 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance for loan losses: Individually evaluated for impairment $ 64 $ — $ — $ 21 $ 147 $ 58 $ 7 $ — $ 297 Collectively evaluated for impairment 26,666 4,344 23,554 19,513 3,487 4,643 8,445 7,225 97,877 Purchased credit-impaired loans — — — 23 57 — — — 80 Total allowance for loan losses $ 26,730 $ 4,344 $ 23,554 $ 19,557 $ 3,691 $ 4,701 $ 8,452 $ 7,225 $ 98,254 Loan balances: Individually evaluated for impairment $ 4,352 $ — $ 2,166 $ 550 $ 3,058 $ 3,582 $ 964 $ — $ 14,672 Collectively evaluated for impairment 3,534,235 402,235 1,077,636 1,597,712 377,333 940,948 788,834 — 8,718,933 Purchased credit-impaired loans 11,714 6 — 526 414 87 198 — 12,945 Total loans $ 3,550,301 $ 402,241 $ 1,079,802 $ 1,598,788 $ 380,805 $ 944,617 $ 789,996 $ — $ 8,746,550 For the Three Months Ended June 30, 2018 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 $ 23,461 $ 2,592 $ 28,766 $ 19,885 $ 2,999 $ 3,779 $ 5,514 $ 5,211 $ 92,207 Provision for loan losses 1,035 1,126 (1,743 ) (469 ) 451 (203 ) 264 1,539 2,000 Recoveries 216 — 11 100 41 356 106 — 830 Charge-offs (299 ) — — (375 ) (329 ) — (159 ) — (1,162 ) Ending balance $ 24,413 $ 3,718 $ 27,034 $ 19,141 $ 3,162 $ 3,932 $ 5,725 $ 6,750 $ 93,875 For the Six Months Ended June 30, 2018 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 $ 22,824 $ 1,633 $ 27,568 $ 18,311 $ 4,053 $ 2,055 $ 3,866 $ 8,718 $ 89,028 Provision for loan losses 320 2,085 (719 ) 1,454 (596 ) 1,247 2,177 (1,968 ) 4,000 Recoveries 1,568 — 185 270 41 646 218 — 2,928 Charge-offs (299 ) — — (894 ) (336 ) (16 ) (536 ) — (2,081 ) Ending balance $ 24,413 $ 3,718 $ 27,034 $ 19,141 $ 3,162 $ 3,932 $ 5,725 $ 6,750 $ 93,875 June 30, 2018 Commercial Real Estate Multifamily Construction and Land Commercial Business Agricultural Business One- to Four-Family Residential Consumer Unallocated Total Allowance for loan losses: Individually evaluated for impairment $ 278 $ — $ — $ 13 $ 59 $ 108 $ 10 $ — $ 468 Collectively evaluated for impairment 24,135 3,718 27,034 19,095 3,043 3,824 5,715 6,750 93,314 Purchased credit-impaired loans — — — 33 60 — — — 93 Total allowance for loan losses $ 24,413 $ 3,718 $ 27,034 $ 19,141 $ 3,162 $ 3,932 $ 5,725 $ 6,750 $ 93,875 Loan balances: Individually evaluated for impairment $ 8,998 $ — $ 750 $ 369 $ 3,298 $ 4,789 $ 205 $ — $ 18,409 Collectively evaluated for impairment 3,155,917 330,220 976,435 1,310,601 333,015 835,560 706,512 — 7,648,260 Purchased credit impaired loans 12,605 164 3,255 1,454 396 121 68 — 18,063 Total loans $ 3,177,520 $ 330,384 $ 980,440 $ 1,312,424 $ 336,709 $ 840,470 $ 706,785 $ — $ 7,684,732

GOODWILL, OTHER INTANGIBLE AS_2

GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Tables)	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Goodwill and Intangible Assets	The following table summarizes the changes in the Company’s goodwill and other intangibles for the six months ended June 30, 2019 and the year ended December 31, 2018 (in thousands): Goodwill CDI LHI Total Balance, December 31, 2017 $ 242,659 $ 22,378 $ 277 $ 265,314 Additions through acquisitions (1) 96,495 16,368 — 112,863 Amortization — (6,047 ) (52 ) (6,099 ) Balance, December 31, 2018 339,154 32,699 225 372,078 Amortization — (4,104 ) (8 ) (4,112 ) Adjustments (2) — — (217 ) (217 ) Balance, June 30, 2019 $ 339,154 $ 28,595 $ — $ 367,749 (1) The additions to goodwill and CDI in 2018 relate to the acquisition of Skagit. (2) The adjustment to LHI represents a reclassification to the right of use lease asset in connection with the implementation of Lease Topic 842.
Schedule of Estimated Annual Amortization Expense	The following table presents the estimated amortization expense with respect to CDI for the periods indicated (in thousands): Estimated Amortization Remainder of 2019 $ 3,853 2020 6,888 2021 5,816 2022 4,651 2023 3,237 Thereafter 4,150 $ 28,595
Schedule of Servicing Assets at Amortized Value	An analysis of our mortgage servicing rights for the three and six months ended June 30, 2019 and 2018 is presented below (in thousands): Three Months Ended Six Months Ended 2019 2018 2019 2018 Balance, beginning of the period $ 14,417 $ 14,617 $ 14,638 $ 14,738 Additions—amounts capitalized 685 863 1,357 1,684 Additions—through purchase 22 30 69 45 Amortization (1) (1,126 ) (989 ) (2,066 ) (1,946 ) Balance, end of the period (2) $ 13,998 $ 14,521 $ 13,998 $ 14,521 (1) Amortization of mortgage servicing rights is recorded as a reduction of loan servicing income within mortgage banking operations and any unamortized balance is fully amortized if the loan repays in full. (2) There was no valuation allowance as of June 30, 2019 and 2018 .

REAL ESTATE OWNED, NET (Tables)

REAL ESTATE OWNED, NET (Tables)	6 Months Ended
	Jun. 30, 2019
Real Estate [Abstract]
Schedule of Changes in Real Estate Owned, Net of Valuation Adjustments	The following table presents the changes in REO for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended Six Months Ended 2019 2018 2019 2018 Balance, beginning of the period $ 2,611 $ 328 $ 2,611 $ 360 Additions from loan foreclosures 61 393 61 521 Proceeds from dispositions of REO (150 ) (314 ) (150 ) (314 ) Gain on sale of REO (9 ) 66 (9 ) 66 Valuation adjustments in the period — — — (160 ) Balance, end of the period $ 2,513 $ 473 $ 2,513 $ 473

DEPOSITS (Tables)

DEPOSITS (Tables)	6 Months Ended
	Jun. 30, 2019
Banking and Thrift [Abstract]
Schedule of Deposit Liabilities	Deposits consisted of the following at June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Non-interest-bearing accounts $ 3,671,995 $ 3,657,817 Interest-bearing checking 1,187,035 1,191,016 Regular savings accounts 1,848,048 1,842,581 Money market accounts 1,511,119 1,465,369 Total interest-bearing transaction and saving accounts 4,546,202 4,498,966 Certificates of deposit: Certificates of deposit less than or equal to $250,000 891,312 1,143,303 Certificates of deposit greater than $250,000 179,458 176,962 Total certificates of deposit (1) 1,070,770 1,320,265 Total deposits $ 9,288,967 $ 9,477,048 Included in total deposits: Public fund transaction and savings accounts $ 223,610 $ 217,401 Public fund interest-bearing certificates 28,656 30,089 Total public deposits $ 252,266 $ 247,490 Total brokered deposits $ 138,395 $ 377,347 (1) Certificates of deposit include $384,000 and $563,000 of acquisition premiums at June 30, 2019 and December 31, 2018 , respectively.
Maturities of Certificates of Deposit	Scheduled maturities and weighted average interest rates of certificate accounts at June 30, 2019 are as follows (dollars in thousands): June 30, 2019 Amount Weighted Average Rate Maturing in one year or less $ 766,901 1.14 % Maturing after one year through two years 196,538 1.65 Maturing after two years through three years 81,540 1.87 Maturing after three years through four years 12,620 1.45 Maturing after four years through five years 10,778 2.24 Maturing after five years 2,393 1.14 Total certificates of deposit $ 1,070,770 1.31 %

FAIR VALUE OF FINANCIAL INSTR_2

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 and December 31, 2018 , whether or not measured at fair value in the Consolidated Statements of Financial Condition (dollars in thousands): June 30, 2019 December 31, 2018 Level Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Assets: Cash and cash equivalents 1 $ 187,043 $ 187,043 $ 272,196 $ 272,196 Securities—trading 3 25,741 25,741 25,896 25,896 Securities—available-for-sale 2 1,561,009 1,561,009 1,636,223 1,636,223 Securities—held-to-maturity 2 200,054 203,749 230,984 229,301 Securities—held-to-maturity 3 3,168 3,168 3,236 3,236 Loans held for sale 2 170,744 171,385 171,031 171,157 Loans receivable 3 8,746,550 8,804,689 8,684,595 8,629,450 FHLB stock 3 34,583 34,583 31,955 31,955 Bank-owned life insurance 1 178,922 178,922 177,467 177,467 Mortgage servicing rights 3 13,998 22,030 14,638 25,813 Equity securities 1 — — 352 352 Derivatives: Interest rate swaps 2 13,604 13,604 3,138 3,138 Interest rate lock and forward sales commitments 2 1,545 1,545 471 471 Liabilities: Demand, interest checking and money market accounts 2 6,370,149 6,370,149 6,314,202 6,314,202 Regular savings 2 1,848,048 1,848,048 1,842,581 1,842,581 Certificates of deposit 2 1,070,770 1,065,200 1,320,265 1,298,238 FHLB advances 2 606,000 609,464 540,189 540,189 Other borrowings 2 118,370 118,370 118,995 118,995 Junior subordinated debentures 3 113,621 113,621 114,091 114,091 Derivatives: Interest rate swaps 2 11,067 11,067 3,138 3,138 Interest rate lock and forward sales commitments 2 1,080 1,080 1,654 1,654
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 June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 Level 1 Level 2 Level 3 Total Assets: Securities—trading Corporate bonds (Trust Preferred Securities) $ — $ — $ 25,741 $ 25,741 — — 25,741 25,741 Securities—available-for-sale U.S. Government and agency obligations — 125,068 — 125,068 Municipal bonds — 110,910 — 110,910 Corporate bonds — 4,561 — 4,561 Mortgage-backed or related securities — 1,312,433 — 1,312,433 Asset-backed securities — 8,037 — 8,037 — 1,561,009 — 1,561,009 Loans held for sale — 149,691 — 149,691 Derivatives Interest rate swaps — 13,604 — 13,604 Interest rate lock and forward sales commitments — 1,545 — 1,545 $ — $ 1,725,849 $ 25,741 $ 1,751,590 Liabilities: Junior subordinated debentures, net of unamortized deferred issuance costs $ — $ — $ 113,621 $ 113,621 Derivatives Interest rate swaps — 11,067 — 11,067 Interest rate lock and forward sales commitments — 1,080 — 1,080 $ — $ 12,147 $ 113,621 $ 125,768 December 31, 2018 Level 1 Level 2 Level 3 Total Assets: Securities—trading Corporate bonds (Trust Preferred Securities) $ — $ — $ 25,896 $ 25,896 — — 25,896 25,896 Securities—available-for-sale U.S. Government and agency obligations — 149,112 — 149,112 Municipal bonds — 117,822 — 117,822 Corporate bonds — 3,495 — 3,495 Mortgage-backed securities — 1,343,861 — 1,343,861 Asset-backed securities — 21,933 — 21,933 — 1,636,223 — 1,636,223 Loans held for sale — 164,767 — 164,767 Equity securities — 352 — 352 Derivatives Interest rate swaps — 3,138 — 3,138 Interest rate lock and forward sales commitments — 471 — 471 $ — $ 1,804,951 $ 25,896 $ 1,830,847 Liabilities: Junior subordinated debentures, net of unamortized deferred issuance costs $ — $ — $ 114,091 $ 114,091 Derivatives Interest rate swaps — 3,138 — 3,138 Interest rate lock and forward sales commitments — 1,654 — 1,654 $ — $ 4,792 $ 114,091 $ 118,883
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 certain of the Company's assets and liabilities classified as Level 3 and measured at fair value on a recurring and non-recurring basis at June 30, 2019 and December 31, 2018 : Weighted Average Rate / Range Financial Instruments Valuation Techniques Unobservable Inputs June 30, 2019 December 31, 2018 Corporate bonds (TPS securities) Discounted cash flows Discount rate 6.32 % 6.81 % Junior subordinated debentures Discounted cash flows Discount rate 6.32 % 6.81 % Impaired loans Collateral Valuations Discount to appraised value 8.50% to 9.00% 0.0% to 8.50% REO Appraisals Discount to appraised value 32.00 % 69.20 %
Schedule of Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	The following tables provide a reconciliation of the assets and liabilities measured at fair value using significant unobservable inputs (Level 3) on a recurring basis during the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended Six Months Ended June 30, 2019 June 30, 2019 Level 3 Fair Value Inputs Level 3 Fair Value Inputs TPS Securities Borrowings—Junior Subordinated Debentures TPS Securities Borrowings— Junior Subordinated Debentures Beginning balance $ 25,838 $ 113,917 $ 25,896 $ 114,091 Total gains or losses recognized Assets losses (97 ) — (155 ) — Liabilities gains — (296 ) — (470 ) Ending balance at June 30, 2019 $ 25,741 $ 113,621 $ 25,741 $ 113,621 Three Months Ended Six Months Ended June 30, 2018 June 30, 2018 Level 3 Fair Value Inputs Level 3 Fair Value Inputs TPS Securities Borrowings—Junior Subordinated Debentures TPS Securities Borrowings— Junior Subordinated Debentures Beginning balance $ 25,474 $ 112,516 $ 22,058 $ 98,707 Total gains or losses recognized Assets gains 66 — 3,482 — Liabilities losses — 258 — 14,067 Ending balance at June 30, 2018 $ 25,540 $ 112,774 $ 25,540 $ 112,774
Schedule of Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis	The following tables present financial assets 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 as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 Level 1 Level 2 Level 3 Total Impaired loans $ — $ — $ 1,225 $ 1,225 REO — — 2,513 2,513 December 31, 2018 Level 1 Level 2 Level 3 Total Impaired loans $ — $ — $ 2,915 $ 2,915 REO — — 2,611 2,611 The following table presents the losses resulting from non-recurring fair value adjustments for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Impaired loans $ (125 ) $ (329 ) $ (425 ) $ (329 ) REO — — — (160 ) Total loss from non-recurring measurements $ (125 ) $ (329 ) $ (425 ) $ (489 )

INCOME TAXES AND DEFERRED TAX_2

INCOME TAXES AND DEFERRED TAXES INCOME TAXES AND DEFERRED TAXES (Tables)	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The following table presents the balances of the Company’s tax credit investments and related unfunded commitments at June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Tax credit investments $ 21,359 $ 17,360 Unfunded commitments—tax credit investments 15,700 12,726 The following table presents other information related to the Company's tax credit investments for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended Six Months Ended 2019 2018 2019 2018 Tax credits and other tax benefits recognized $ 494 $ 364 $ 988 $ 728 Tax credit amortization expense included in provision for income taxes 405 288 810 575

CALCULATION OF WEIGHTED AVERA_2

CALCULATION OF WEIGHTED AVERAGE SHARES OUTSTANDING FOR EARNINGS PER SHARE (EPS) (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Weighted Shares Outstanding	The following table reconciles basic to diluted weighted average shares outstanding used to calculate earnings per share data for the three and six months ended June 30, 2019 and 2018 (in thousands, except shares and per share data): Three Months Ended Six Months Ended 2019 2018 2019 2018 Net income $ 39,700 $ 32,424 $ 73,046 $ 61,214 Basic weighted average shares outstanding 34,831,047 32,250,514 34,940,106 32,323,635 Plus unvested restricted stock 51,312 81,095 88,775 98,652 Diluted weighted shares outstanding 34,882,359 32,331,609 35,028,881 32,422,287 Earnings per common share Basic $ 1.14 $ 1.01 $ 2.09 $ 1.89 Diluted $ 1.14 $ 1.00 $ 2.09 $ 1.89

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of Financial Instruments With Off-Balance-Sheet Risks	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 June 30, 2019 December 31, 2018 Commitments to extend credit $ 2,934,838 $ 2,837,981 Standby letters of credit and financial guarantees 15,529 17,784 Commitments to originate loans 61,037 32,145 Risk participation agreement 41,057 24,091 Derivatives also included in Note 14: Commitments to originate loans held for sale 110,648 31,728 Commitments to sell loans secured by one- to four-family residential properties 46,726 18,328 Commitments to sell securities related to mortgage banking activities 225,703 144,250

DERIVATIVES AND HEDGING (Tables

DERIVATIVES AND HEDGING (Tables)	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivatives Designated in Hedge Relationships	As of June 30, 2019 and December 31, 2018 , 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 June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 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 $ 3,773 $ 279 $ 3,973 $ 270 $ 3,773 $ 279 $ 3,973 $ 270 (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 Derivatives Not Designated in Hedge Relationships	As of June 30, 2019 and December 31, 2018 , 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 June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 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 $ 287,416 $ 13,325 $ 272,374 $ 2,868 $ 287,416 $ 10,788 $ 272,374 $ 2,868 Mortgage loan commitments 88,810 1,373 20,229 273 42,890 45 17,763 187 Forward sales contracts 46,726 172 18,328 198 225,703 1,035 144,250 1,467 $ 422,952 $ 14,870 $ 310,931 $ 3,339 $ 556,009 $ 11,868 $ 434,387 $ 4,522 (1) Included in Other assets on the Consolidated Statements of Financial Condition, with the exception of certain interest swaps and mortgage loan commitments (with a fair value of $406,000 at June 30, 2019 and $282,000 at December 31, 2018 ), which are included in Loans receivable. (2) Included in Other liabilities on the Consolidated Statements of Financial Condition. Gains (losses) recognized in income on derivatives not designated in hedge relationships for the three and six months ended June 30, 2019 and 2018 were as follows (in thousands): Location on Consolidated Statements of Operations Three Months Ended Six Months Ended 2019 2018 2019 2018 Mortgage loan commitments Mortgage banking operations $ 1,093 $ 96 $ 1,100 $ 164 Forward sales contracts Mortgage banking operations (392 ) (73 ) (242 ) 268 $ 701 $ 23 $ 858 $ 432
Offsetting Assets and Liabilities	as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 Gross Amounts of Financial Instruments Not Offset in the Consolidated Statements 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 $ 13,621 $ (17 ) $ 13,604 $ — $ — $ 13,604 $ 13,621 $ (17 ) $ 13,604 $ — $ — $ 13,604 Derivative liabilities Interest rate swaps $ 13,621 $ (2,554 ) $ 11,067 $ — $ (10,919 ) $ 148 $ 13,621 $ (2,554 ) $ 11,067 $ — $ (10,919 ) $ 148 December 31, 2018 Gross Amounts of Financial Instruments Not Offset in the Consolidated Statements 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 $ 5,038 $ (1,900 ) $ 3,138 $ — $ — $ 3,138 $ 5,038 $ (1,900 ) $ 3,138 $ — $ — $ 3,138 Derivative liabilities Interest rate swaps $ 5,038 $ (1,900 ) $ 3,138 $ — $ (1,320 ) $ 1,818 $ 5,038 $ (1,900 ) $ 3,138 $ — $ (1,320 ) $ 1,818

REVENUE FROM CONTRACTS WITH C_2

REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue [Table Text Block]	Deposit fees and other service charges for the three and six months ended June 30, 2019 and 2018 are summarized as follows (in thousands): Three Months Ended Six Months Ended 2019 2018 2019 2018 Deposit service charges $ 4,829 $ 4,528 $ 9,416 $ 8,848 Debit and credit card interchange fees 9,272 7,872 17,203 15,191 Debit and credit card expense (1,949 ) (1,933 ) (4,398 ) (3,903 ) Merchant services income 3,345 2,513 6,201 4,774 Merchant services expense (2,661 ) (1,924 ) (4,981 ) (3,729 ) Other service charges 1,210 929 3,223 2,100 Total deposit fees and other service charges $ 14,046 $ 11,985 $ 26,664 $ 23,281

LEASES (Tables)

LEASES (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Lease, Costs	Lease Position as of June 30, 2019 The table below presents the lease right-of-use assets and lease liabilities recorded on the balance sheet at June 30, 2019 (dollars in thousands): Classification on the Balance Sheet June 30, 2019 Assets Operating right-of-use lease assets Other assets $ 54,515 Liabilities Operating lease liabilities Accrued expenses and other liabilities $ 57,638 Weighted-average remaining lease term Operating leases 5.8 years Weighted-average discount rate Operating leases 4.24 % Lease Costs The table below presents certain information related to the lease costs for operating leases for the three and six months ended June 30, 2019 (in thousands): Three Months Ended Six Months Ended 2019 2019 Operating lease cost (1) $ 3,858 $ 7,832 Short-term lease cost (1) 99 222 Variable lease cost (1) 567 1,128 Less sublease income (1) (231 ) (468 ) Total lease cost $ 4,293 $ 8,714 (1) Lease expenses and sublease income are classified within occupancy and equipment expense on the Consolidated Statements of Operations.
Lessee, Operating Lease, Liability, Maturity	The table below reconciles the undiscounted cash flows for each of the first five years beginning with 2019 and the total of the remaining years to the operating lease liabilities recorded on the Consolidated Statements of Financial Position (in thousands): Operating Leases Remainder of 2019 $ 7,514 2020 14,330 2021 12,611 2022 9,083 2023 6,011 Thereafter 15,659 Total minimum lease payments 65,208 Less: amount of lease payments representing interest (7,570 ) Lease obligations $ 57,638

ACCOUNTING STANDARDS RECENTLY_2

ACCOUNTING STANDARDS RECENTLY ISSUED OR ADOPTED (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating right-of-use lease assets	$ 54,515
Operating lease liabilities	$ 57,638
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating right-of-use lease assets		$ 56,000
Operating lease liabilities		$ 59,000

BUSINESS COMBINATION (Details)

BUSINESS COMBINATION (Details) $ in Thousands, shares in Millions	Nov. 01, 2018USD ($)shares	Jun. 30, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Business Acquisition [Line Items]
Goodwill		$ 339,154	$ 339,154	$ 242,659
Nonaccretable difference		$ (6,200)
Skagit Bank [Member]
Business Acquisition [Line Items]
Percentage of voting interest acquired	100.00%
Number of branches acquired	11
Shares transferred as consideration (in shares) | shares	3.1
Total consideration paid	$ 180,038
Assets acquired	915,821
Deposits recognized	810,200
Loans receivable (contractual amount of $645.6 million)	632,374
Core deposit intangible	16,368
Goodwill	$ 96,495
Acquired intangible asset, useful life	9 years
Unpaid principal balance on non-credit-impaired loans	$ 637,400
Fair value on non-credit-impaired loans	625,200
Discount on acquired loans	12,200
Credit related discount	7,900
Contractually required principal and interest payments	9,897
Nonaccretable difference	(1,915)
Cash flows expected to be collected	7,982
Accretable yield	(995)
Fair value of PCI loans	$ 6,987

BUSINESS COMBINATION - Purchase

BUSINESS COMBINATION - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Nov. 01, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill	$ 339,154	$ 339,154		$ 242,659
Skagit Bank [Member]
Business Acquisition [Line Items]
Cash paid			$ 329
Fair value of common shares issued			179,709
Total consideration			180,038
Cash and cash equivalents			19,167
Securities			210,326
Loans receivable (contractual amount of $645.6 million)			632,374
Real estate owned held for sale			2,593
Property and equipment			15,788
Core deposit intangible			16,368
Deferred tax asset			95
Other assets			19,110
Total assets acquired			915,821
Deposits			810,209
Other liabilities			22,069
Total liabilities assumed			832,278
Net assets acquired			83,543
Goodwill			96,495
Business Combination, Acquired Receivables, Gross Contractual Amount			$ 645,600

SECURITIES (Schedule of Securit

SECURITIES (Schedule of Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Securities [Line Items]
Securities—trading, Amortized Cost	$ 27,203	$ 27,203
Securities—trading	25,741	25,896
Available-for-sale Securities, Amortized Cost	1,535,775	1,648,421
Available-for-sale Securities, Gross Unrealized Gains	27,751	7,171
Available-for-sale Securities, Gross Unrealized Losses	(2,517)	(19,369)
Securities—available-for-sale	1,561,009	1,636,223
Held-to-maturity Securities, Amortized Cost	203,222	234,220
Held-to-maturity Securities, Gross Unrealized Gains	4,365	1,807
Held-to-maturity Securities, Gross Unrealized Losses	670	3,490
Securities—held-to-maturity	206,917	232,537
U.S. Government and agency obligations [Member]
Schedule of Securities [Line Items]
Available-for-sale Securities, Amortized Cost	125,597	151,012
Available-for-sale Securities, Gross Unrealized Gains	437	149
Available-for-sale Securities, Gross Unrealized Losses	(966)	(2,049)
Securities—available-for-sale	125,068	149,112
Held-to-maturity Securities, Amortized Cost	388	1,006
Held-to-maturity Securities, Gross Unrealized Gains	6	14
Held-to-maturity Securities, Gross Unrealized Losses	0	1
Securities—held-to-maturity	394	1,019
Municipal bonds [Member]
Schedule of Securities [Line Items]
Available-for-sale Securities, Amortized Cost	106,379	116,548
Available-for-sale Securities, Gross Unrealized Gains	4,549	1,806
Available-for-sale Securities, Gross Unrealized Losses	(18)	(532)
Securities—available-for-sale	110,910	117,822
Held-to-maturity Securities, Amortized Cost	148,580	176,663
Held-to-maturity Securities, Gross Unrealized Gains	3,538	1,727
Held-to-maturity Securities, Gross Unrealized Losses	629	2,578
Securities—held-to-maturity	151,489	175,812
Corporate bonds [Member]
Schedule of Securities [Line Items]
Securities—trading, Amortized Cost	27,203	27,203
Securities—trading	25,741	25,896
Available-for-sale Securities, Amortized Cost	4,557	3,556
Available-for-sale Securities, Gross Unrealized Gains	12	0
Available-for-sale Securities, Gross Unrealized Losses	(8)	(61)
Securities—available-for-sale	4,561	3,495
Held-to-maturity Securities, Amortized Cost	3,668	3,736
Held-to-maturity Securities, Gross Unrealized Gains	0	0
Held-to-maturity Securities, Gross Unrealized Losses	12	13
Securities—held-to-maturity	3,656	3,723
Mortgage-backed or related securities [Member]
Schedule of Securities [Line Items]
Available-for-sale Securities, Amortized Cost	1,291,166	1,355,258
Available-for-sale Securities, Gross Unrealized Gains	22,751	5,210
Available-for-sale Securities, Gross Unrealized Losses	(1,484)	(16,607)
Securities—available-for-sale	1,312,433	1,343,861
Held-to-maturity Securities, Amortized Cost	50,586	52,815
Held-to-maturity Securities, Gross Unrealized Gains	821	66
Held-to-maturity Securities, Gross Unrealized Losses	29	898
Securities—held-to-maturity	51,378	51,983
Asset-backed Securities [Member]
Schedule of Securities [Line Items]
Available-for-sale Securities, Amortized Cost	8,076	22,047
Available-for-sale Securities, Gross Unrealized Gains	2	6
Available-for-sale Securities, Gross Unrealized Losses	(41)	(120)
Securities—available-for-sale	$ 8,037	$ 21,933

SECURITIES (Securities with Con

SECURITIES (Securities with Continuous Loss Position) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 82,093	$ 412,162
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(527)	(4,313)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	284,527	659,936
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,990)	(15,056)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	366,620	1,072,098
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(2,517)	(19,369)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	2,211	40,804
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1	495
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	29,994	75,159
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(669)	(2,995)
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	32,205	115,963
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	670	3,490
U.S. Government and agency obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	0	75,885
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	(1,240)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	71,611	50,508
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(966)	(809)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	71,611	126,393
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(966)	(2,049)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value		145
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		1
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value		0
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value		145
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss		1
Municipal bonds [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	493	6,422
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(3)	(54)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	3,230	27,231
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(15)	(478)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	3,723	33,653
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(18)	(532)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	0	29,898
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	274
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	23,378	44,637
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(629)	(2,304)
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	23,378	74,535
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	629	2,578
Corporate bonds [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	352	3,199
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1)	(56)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	1,798	295
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(7)	(5)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,150	3,494
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(8)	(61)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	0	0
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	488	487
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(12)	(13)
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	488	487
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	12	13
Mortgage-backed or related securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	73,934	316,074
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(483)	(2,939)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	207,659	571,989
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,001)	(13,668)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	281,593	888,063
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(1,484)	(16,607)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	2,211	10,761
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1	220
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	6,128	30,035
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(28)	(678)
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	8,339	40,796
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	29	898
Asset-backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	7,314	10,582
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(40)	(24)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	229	9,913
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1)	(96)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	7,543	20,495
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (41)	$ (120)

SECURITIES (Securities Debt Mat

SECURITIES (Securities Debt Maturities) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Trading Securities, Amortized Cost, Maturing in one year or less	$ 0
Trading Securities, Amortized Cost, Maturing after one year through five years	0
Trading Securities, Amortized Cost, Maturing after five years through ten years	0
Trading Securities, Amortized Cost, Maturing after ten years through twenty years	27,203
Trading Securities, Amortized Cost, Maturing after twenty years	0
Trading Securities, Amortized Cost	27,203	$ 27,203
Trading Securities, Fair Value, Maturing in one year or less	0
Trading Securities, Fair Value, Maturing after one year through five years	0
Trading Securities, Fair Value, Maturing after five years through ten years	0
Trading Securities, Fair Value, Maturing after ten years through twenty years	25,741
Trading Securities, Fair Value, Maturing after twenty years	0
Trading Securities, Fair Value	25,741	25,896
Available-for-sale Securities, Amortized Cost, Maturing in one year or less	2,554
Available-for-sale Securities, Amortized Cost, Maturing after one year through five years	57,247
Available-for-sale Securities, Amortized Cost, Maturing after five years through ten years	393,053
Available-for-sale Securities, Amortized Cost, Maturing after ten years through twenty years	178,802
Available-for-sale Securities, Amortized Cost, Maturing after twenty years	904,119
Available-for-sale Securities, Amortized Cost	1,535,775	1,648,421
Available-for-sale Securities, Fair Value, Maturing in one year or less	2,556
Available-for-sale Securities, Fair Value, Maturing after one year through five years	58,238
Available-for-sale Securities, Fair Value, Maturing after five years through ten years	404,449
Available-for-sale Securities, Fair Value, Maturing after ten years through twenty years	183,689
Available-for-sale Securities, Fair Value, Maturing after twenty years	912,077
Available-for-sale Securities, Fair Value	1,561,009	1,636,223
Held-to-maturity Securities, Amortized Cost, Maturing in one year or less	4,602
Held-to-maturity Securities, Amortized Cost, Maturing after one year through five years	63,805
Held-to-maturity Securities, Amortized Cost, Maturing after five years through ten years	43,943
Held-to-maturity Securities, Amortized Cost, Maturing after ten years through twenty years	58,805
Held-to-maturity Securities, Amortized Cost, Maturing after twenty years	32,067
Held-to-maturity Securities, Amortized Cost	203,222	234,220
Held-to-maturity Securities, Fair Value, Maturing in one year or less	4,604
Held-to-maturity Securities, Fair Value, Maturing after one year through five years	64,663
Held-to-maturity Securities, Fair Value, Maturing after five years through ten years	45,457
Held-to-maturity Securities, Fair Value, Maturing after ten years through twenty years	60,672
Held-to-maturity Securities, Fair Value, Maturing after twenty years	31,521
Debt Securities, Held-to-maturity, Fair Value	$ 206,917	$ 232,537

SECURITIES (Securities Pledged)

SECURITIES (Securities Pledged) (Details) $ in Thousands	Jun. 30, 2019USD ($)
Pledged Financial Instruments, Not Separately Reported, Securities [Abstract]
Securities pledged for State and Local Government Public Deposits, Carrying Value	$ 136,556
Securities pledged for Interest Rate Swap Counterparties, Carrying Value	15,560
Securities pledged for Repurchase Agreements, Carrying Value	144,625
Pledged Financial Instruments, Not Separately Reported, Interest-bearing Deposits for Other Debt Facilities	2,721
Total pledged securities, Carrying Value	299,462
Securities pledged for State and Local Government public deposits, Amortized Cost	136,217
Securities pledged for Interest Rate Swap Counterparties, Amortized Cost	15,494
Securities pledged for Repurchase Agreements, Amortized Cost	142,411
Pledged Financial Instruments, Not Separately Reported, Interest-bearing Deposits for Other Debt Facilities, Amortized Cost	2,721
Total pledged securities, Amortized Cost	296,843
Securities pledged for State and Local Government Public Deposits, Fair Value	139,723
Securities pledged for Interest Rate Swap Counterparties, Fair Value	15,741
Securities pledged for Retail Repurchase Agreements, Fair Value	144,625
Pledged Financial Instruments, Not Separately Reported, Interest-bearing Deposits for Other Debt Facilities, Fair Value	2,698
Total pledged securities, Fair Value	$ 302,787

SECURITIES (Textual) (Details)

SECURITIES (Textual) (Details)	6 Months Ended
	Jun. 30, 2019USD ($)security	Jun. 30, 2018USD ($)security	Dec. 31, 2018security
Investments, Debt and Equity Securities [Abstract]
Trading Securities, Sale Proceeds	$ 0	$ 1,300,000
Trading Securities, Realized Gain (Loss)	0	28,000
Trading Securities, OTTI (Recovery) Charges	$ 0	$ 0
Trading Securities, Number of Securities on Nonaccrual Status | security	0	0
Trading Securities, Unrealized Holding Loss	$ 103,000
Trading Securities, Unrealized Holding Gain		$ 3,400,000
Debt Securities, Available-for-sale [Abstract]
Available-for-sale Securities, Number of Securities in Unrealized Loss Position | security	105		271
Available-for-sale Securities, Gross Realized Gains (Losses), Number of Securities Sold | security	36
Available-for-sale Securities, Sale Proceeds	$ 40,800,000	0
Available-for-sale Securities, Gross Realized Gain (Loss)	(26,000)	51,000,000
Available-for-sale Securities, OTTI Charges	$ 0	$ 0
Available-for-sale Securities, Number of Securities in Nonaccrual Status | security	0	0
Debt Securities, Held-to-maturity, Sold, Realized Gain (Loss), Excluding Other-than-temporary Impairment	$ (1,000)	$ 2,000,000
Held-to-maturity Securities [Abstract]
Held-to-maturity Securities, Number of Securities in Unrealized Loss Position | security	14		90
Held-to-maturity Securities, Number of Securities Sold | security	1	0
Held-to-maturity Securities, OTTI Charges	$ 0	$ 0
Held-to-maturity Securities, Number of Securities in Nonaccrual Status | security	0	0

LOANS RECEIVABLE AND THE ALLO_3

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Loans by Type) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 8,746,550		$ 8,684,595	$ 7,684,732
Allowance for loan losses	98,254	$ 97,308	96,485	93,875	$ 92,207	$ 89,028
Net loans	$ 8,648,296		$ 8,588,110
Percent of total loans	100.00%		100.00%
Unearned loan fees in excess of unamortized costs	$ 847		$ (1,400)
Discount on acquired loans, net	22,600		25,700
Commerical real estate - owner-occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 1,433,995		$ 1,430,097
Percent of total loans	16.40%		16.40%
Commercial real estate - investment properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 2,116,306		$ 2,131,059
Percent of total loans	24.20%		24.50%
Multifamily real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 402,241		$ 368,836	330,384
Allowance for loan losses	$ 4,344	4,020	$ 3,818	3,718	2,592	1,633
Percent of total loans	4.60%		4.20%
Commercial construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 172,931		$ 172,410
Percent of total loans	2.00%		2.00%
Multifamily Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 189,160		$ 184,630
Percent of total loans	2.20%		2.10%
One- to four-family construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 503,061		$ 534,678
Percent of total loans	5.70%		6.20%
Land and land development - residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 187,180		$ 188,508
Percent of total loans	2.10%		2.20%
Land and land development - commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 27,470		$ 27,278
Percent of total loans	0.30%		0.30%
Commercial business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 1,598,788		$ 1,483,614	1,312,424
Allowance for loan losses	$ 19,557	18,662	$ 19,438	19,141	19,885	18,311
Percent of total loans	18.30%		17.10%
Agricultural business, including secured by farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 380,805		$ 404,873	336,709
Allowance for loan losses	$ 3,691	3,596	$ 3,778	3,162	2,999	4,053
Percent of total loans	4.30%		4.70%
One- to four-family residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 944,617		$ 973,616	840,470
Allowance for loan losses	$ 4,701	$ 4,711	$ 4,714	$ 3,932	$ 3,779	$ 2,055
Percent of total loans	10.80%		11.20%
Consumer secured by one- to four-family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 575,658		$ 568,979
Percent of total loans	6.60%		6.60%
Consumer - other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 214,338		$ 216,017
Percent of total loans	2.50%		2.50%

LOANS RECEIVABLE AND THE ALLO_4

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Purchased Credit-Impaired Loans, Changes in Accretable Yield) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Receivables [Abstract]
Outstanding contractual unpaid balance of purchased credit-impaired loans	$ 20,200		$ 20,200		$ 22,000
Carrying balance of purchased credit-impaired loans	12,945	$ 18,063	12,945	$ 18,063	14,413
Accretable Yield Movement Schedule [Roll Forward]
Balance, beginning of period	4,778	6,288	5,216	6,520
Accretion to interest income	(456)	(734)	(949)	(1,831)
Disposals	0	0	0	58
Reclassifications from non-accretable difference	421	555	476	1,362
Balance, end of period	4,743	$ 6,109	4,743	$ 6,109
Certain Loans Acquired in Transfer, Nonaccretable Difference	$ 6,200		$ 6,200
Non-accretable difference					$ 7,100

LOANS RECEIVABLE AND THE ALLO_5

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Impaired Loans With and Without Specific Reserves) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	$ 27,926		$ 27,926		$ 31,813
Recorded Investment, Without Allowance	18,738		18,738		17,765
Recorded Investment, With Allowance	6,265		6,265		11,311
Related Allowance	297		297		416
Average Recorded Investment	27,506	$ 30,291	29,502	$ 35,298
Interest Income Recognized	121	178	302	412
Commerical real estate - owner-occupied [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	3,171		3,171		3,193
Recorded Investment, Without Allowance	2,792		2,792		2,768
Recorded Investment, With Allowance	200		200		200
Related Allowance	20		20		19
Average Recorded Investment	3,072	3,544	3,261	4,464
Interest Income Recognized	2	2	4	5
Commercial real estate - investment properties [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	2,961		2,961		7,287
Recorded Investment, Without Allowance	1,612		1,612		1,320
Recorded Investment, With Allowance	699		699		5,606
Related Allowance	44		44		226
Average Recorded Investment	3,283	7,561	5,255	8,767
Interest Income Recognized	22	75	98	158
Multifamily real estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance					1,901
Recorded Investment, Without Allowance					1,427
Recorded Investment, With Allowance					0
Related Allowance					0
Commercial construction [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	1,153	0	1,290	0
Interest Income Recognized	0	0	0	0
Multifamily Construction [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	1,079		1,079
Recorded Investment, Without Allowance	605		605
Recorded Investment, With Allowance	0		0
Related Allowance	0		0
One- to four-family construction [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	1,181		1,181		919
Recorded Investment, Without Allowance	1,181		1,181		919
Recorded Investment, With Allowance	0		0		0
Related Allowance	0		0		0
Average Recorded Investment	1,006	314	963	459
Interest Income Recognized	1	0	1	4
Land and land development - residential [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	1,026		1,026		1,134
Recorded Investment, Without Allowance	690		690		798
Recorded Investment, With Allowance	0		0		0
Related Allowance	0		0		0
Average Recorded Investment	690	1,582	708	1,190
Interest Income Recognized	0	10	0	10
Land and land development - commercial [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance					44
Recorded Investment, Without Allowance					44
Recorded Investment, With Allowance					0
Related Allowance					0
Commercial business [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	4,393		4,393		4,014
Recorded Investment, Without Allowance	2,984		2,984		2,937
Recorded Investment, With Allowance	550		550		391
Related Allowance	21		21		16
Average Recorded Investment	3,762	3,206	3,782	3,606
Interest Income Recognized	6	5	11	12
Agricultural business, including secured by farmland [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	3,903		3,903		4,863
Recorded Investment, Without Allowance	1,359		1,359		1,751
Recorded Investment, With Allowance	2,320		2,320		2,561
Related Allowance	147		147		96
Average Recorded Investment	4,590	4,357	4,854	6,733
Interest Income Recognized	29	23	56	56
One- to four-family residential [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	6,513		6,513		6,724
Recorded Investment, Without Allowance	4,188		4,188		4,314
Recorded Investment, With Allowance	2,307		2,307		2,358
Related Allowance	58		58		51
Average Recorded Investment	6,449	8,226	6,448	8,559
Interest Income Recognized	57	59	122	160
Consumer secured by one- to four-family [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	3,269		3,269		1,622
Recorded Investment, Without Allowance	2,983		2,983		1,438
Recorded Investment, With Allowance	130		130		133
Related Allowance	5		5		6
Average Recorded Investment	3,129	1,360	2,596	1,375
Interest Income Recognized	3	3	8	5
Consumer - other [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	430		430		112
Recorded Investment, Without Allowance	344		344		49
Recorded Investment, With Allowance	59		59		62
Related Allowance	2		2		$ 2
Average Recorded Investment	372	141	345	145
Interest Income Recognized	$ 1	$ 1	$ 2	$ 2

LOANS RECEIVABLE AND THE ALLO_6

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Troubled Debt Restructuring) (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)contract	Jun. 30, 2019USD ($)contract	Jun. 30, 2018contract	Dec. 31, 2018USD ($)
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	$ 6,594,000	$ 6,594,000		$ 13,422,000
TDRs on Nonaccrual Status	1,552,000	1,552,000		317,000
Total TDRs	8,146,000	8,146,000		13,739,000
Commitments to advance funds related to TDRs, maximum additional amounts	$ 49,000	$ 49,000		0
Number of Contracts | contract	2	3	0
Pre-modification Outstanding Recorded Investment	$ 756,000	$ 1,846,000
Post-modification Outstanding Recorded Investment	756,000	1,846,000
Commerical real estate - owner-occupied [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	0	0		200,000
TDRs on Nonaccrual Status	273,000	273,000		78,000
Total TDRs	273,000	273,000		278,000
Commercial real estate - investment properties [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	699,000	699,000		5,606,000
TDRs on Nonaccrual Status	1,077,000	1,077,000		0
Total TDRs	$ 1,776,000	$ 1,776,000		5,606,000
Number of Contracts | contract	0	1
Pre-modification Outstanding Recorded Investment	$ 0	$ 1,090,000
Post-modification Outstanding Recorded Investment	0	1,090,000
Commercial business [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	550,000	550,000		391,000
TDRs on Nonaccrual Status	0	0		0
Total TDRs	$ 550,000	$ 550,000		391,000
Number of Contracts | contract	1	1
Pre-modification Outstanding Recorded Investment	$ 160,000	$ 160,000
Post-modification Outstanding Recorded Investment	160,000	160,000
Agricultural business, including secured by farmland [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	2,320,000	2,320,000		2,561,000
TDRs on Nonaccrual Status	0	0		0
Total TDRs	$ 2,320,000	$ 2,320,000		2,561,000
Number of Contracts | contract	1	1
Pre-modification Outstanding Recorded Investment	$ 596,000	$ 596,000
Post-modification Outstanding Recorded Investment	596,000	596,000
One- to four-family residential [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	2,836,000	2,836,000		4,469,000
TDRs on Nonaccrual Status	202,000	202,000		239,000
Total TDRs	3,038,000	3,038,000		4,708,000
Consumer secured by one- to four-family [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	130,000	130,000		133,000
TDRs on Nonaccrual Status	0	0		0
Total TDRs	130,000	130,000		133,000
Consumer - other [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	59,000	59,000		62,000
TDRs on Nonaccrual Status	0	0		0
Total TDRs	$ 59,000	$ 59,000		$ 62,000

LOANS RECEIVABLE AND THE ALLO_7

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Newly Restructured Loans) (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)contract	Jun. 30, 2019USD ($)contract	Jun. 30, 2018contract	Dec. 31, 2018USD ($)
Financing Receivable, Modifications [Line Items]
Commitments to advance funds related to TDRs, maximum additional amounts | $	$ 49,000	$ 49,000		$ 0
Number of Contracts	2	3	0
Agricultural business, including secured by farmland [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	1

LOANS RECEIVABLE AND THE ALLO_8

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Troubled Debt Restructuring Which Incurred Payment Default) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
TDRs Which Incurred a Payment Default	$ 0	$ 0

LOANS RECEIVABLE AND THE ALLO_9

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Risk-Rated and Non-Risk Rated Loans by Grade and Other Characteristic) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	$ 8,746,550	$ 8,684,595	$ 7,684,732
Owner-occupied Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	1,433,995	1,430,097
Commercial real estate - investment properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	2,116,306	2,131,059
Multifamily real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	402,241	368,836	330,384
Commercial construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	172,931	172,410
Multifamily Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	189,160	184,630
One- to four-family construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	503,061	534,678
Land and land development - residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	187,180	188,508
Land and land development - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	27,470	27,278
Commercial business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	1,598,788	1,483,614	1,312,424
Agricultural Business/Farmland [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	380,805	404,873	336,709
One- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	944,617	973,616	$ 840,470
Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	575,658	568,979
Consumer Borrower [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	214,338	216,017
Pass (Risk Ratings 1-5) [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	8,628,532	8,557,839
Pass (Risk Ratings 1-5) [Member] | Owner-occupied Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	1,409,358	1,396,721
Pass (Risk Ratings 1-5) [Member] | Commercial real estate - investment properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	2,107,989	2,122,621
Pass (Risk Ratings 1-5) [Member] | Multifamily real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	401,810	368,262
Pass (Risk Ratings 1-5) [Member] | Commercial construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	160,616	159,167
Pass (Risk Ratings 1-5) [Member] | Multifamily Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	189,160	184,630
Pass (Risk Ratings 1-5) [Member] | One- to four-family construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	502,142	533,759
Pass (Risk Ratings 1-5) [Member] | Land and land development - residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	186,490	187,710
Pass (Risk Ratings 1-5) [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	27,434	27,200
Pass (Risk Ratings 1-5) [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	1,549,519	1,436,733
Pass (Risk Ratings 1-5) [Member] | Small Credit-Scored Business Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	744,800	590,900
Pass (Risk Ratings 1-5) [Member] | Agricultural Business/Farmland [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	368,172	392,318
Pass (Risk Ratings 1-5) [Member] | One- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	940,607	969,011
Pass (Risk Ratings 1-5) [Member] | Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	571,458	564,001
Pass (Risk Ratings 1-5) [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	213,777	215,706
Special mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	37,261	31,162
Special mention [Member] | Owner-occupied Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	7,880	6,963
Special mention [Member] | Commercial real estate - investment properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention [Member] | Multifamily real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention [Member] | Commercial construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	11,816
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] | Land and land development - residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	21,832	7,661
Special mention [Member] | Agricultural Business/Farmland [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	7,109	4,214
Special mention [Member] | One- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	434	499
Special mention [Member] | Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	6	9
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	80,679	95,507
Substandard [Member] | Owner-occupied Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	16,757	26,413
Substandard [Member] | Commercial real estate - investment properties [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	8,317	8,438
Substandard [Member] | Multifamily real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	431	574
Substandard [Member] | Commercial construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	12,315	1,427
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	919	919
Substandard [Member] | Land and land development - residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	690	798
Substandard [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	36	78
Substandard [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	27,359	39,133
Substandard [Member] | Agricultural Business/Farmland [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	5,524	8,341
Substandard [Member] | One- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	3,576	4,106
Substandard [Member] | Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	4,200	4,978
Substandard [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	555	302
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	78	87
Doubtful [Member] | Owner-occupied Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful [Member] | Commercial real estate - investment properties [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] | Land and land development - residential [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	78	87
Doubtful [Member] | Agricultural Business/Farmland [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful [Member] | One- to four-family [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	0	0
Doubtful [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
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] | Commercial real estate - investment properties [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] | Land and land development - residential [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/Farmland [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Loss [Member] | One- to four-family [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

LOANS RECEIVABLE AND THE ALL_10

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Age Analysis of Company's Past Due Loans) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 34,419	$ 38,202
Purchased Credit-Impaired	12,945	14,413	$ 18,063
Current	8,699,186	8,631,980
Total loans	8,746,550	8,684,595	7,684,732
Loans 90 days or more past due and still accruing	1,355	906
Nonaccrual loans	17,054	14,748
Commerical real estate - owner-occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,644	3,527
Purchased Credit-Impaired	8,413	8,531
Current	1,421,938	1,418,039
Total loans	1,433,995	1,430,097
Loans 90 days or more past due and still accruing	0	0
Nonaccrual loans	2,991	2,768
Commercial real estate - investment properties [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,760	1,523
Purchased Credit-Impaired	3,301	3,462
Current	2,111,245	2,126,074
Total loans	2,116,306	2,131,059
Loans 90 days or more past due and still accruing	0	0
Nonaccrual loans	1,612	1,320
Multifamily real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	91	317
Purchased Credit-Impaired	6	138	164
Current	402,144	368,381
Total loans	402,241	368,836	330,384
Loans 90 days or more past due and still accruing	0	0
Nonaccrual loans	0	0
Commercial construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	605	1,427
Purchased Credit-Impaired	0	0
Current	172,326	170,983
Total loans	172,931	172,410
Loans 90 days or more past due and still accruing	0	0
Nonaccrual loans	605	1,427
Multifamily Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Purchased Credit-Impaired	0	0
Current	189,160	184,630
Total loans	189,160	184,630
Loans 90 days or more past due and still accruing	0	0
Nonaccrual loans	0	0
One- to four-family construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,635	6,778
Purchased Credit-Impaired	0	137
Current	499,426	527,763
Total loans	503,061	534,678
Loans 90 days or more past due and still accruing	262	0
Nonaccrual loans	919	919
Land and land development - residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	690	1,248
Purchased Credit-Impaired	0	0
Current	186,490	187,260
Total loans	187,180	188,508
Loans 90 days or more past due and still accruing	0	0
Nonaccrual loans	690	798
Land and land development - commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	78
Purchased Credit-Impaired	0	0
Current	27,470	27,200
Total loans	27,470	27,278
Loans 90 days or more past due and still accruing	0	0
Nonaccrual loans	0	44
Commercial business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12,088	7,043
Purchased Credit-Impaired	526	1,028	1,454
Current	1,586,174	1,475,543
Total loans	1,598,788	1,483,614	1,312,424
Loans 90 days or more past due and still accruing	1	1
Nonaccrual loans	2,983	2,936
Agricultural business, including secured by farmland [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,520	3,462
Purchased Credit-Impaired	414	493	396
Current	378,871	400,918
Total loans	380,805	404,873	336,709
Loans 90 days or more past due and still accruing	0	0
Nonaccrual loans	1,359	1,751
One- to four-family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,541	8,887
Purchased Credit-Impaired	87	101	121
Current	938,989	964,628
Total loans	944,617	973,616	$ 840,470
Loans 90 days or more past due and still accruing	995	658
Nonaccrual loans	2,665	1,544
Consumer secured by one- to four-family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,903	2,607
Purchased Credit-Impaired	113	432
Current	571,642	565,940
Total loans	575,658	568,979
Loans 90 days or more past due and still accruing	66	238
Nonaccrual loans	2,917	1,201
Consumer - other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	942	1,305
Purchased Credit-Impaired	85	91
Current	213,311	214,621
Total loans	214,338	216,017
Loans 90 days or more past due and still accruing	31	9
Nonaccrual loans	313	40
30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	13,084	18,270
30 to 59 Days Past Due [Member] | Commerical real estate - owner-occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,024	785
30 to 59 Days Past Due [Member] | Commercial real estate - investment properties [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	148	91
30 to 59 Days Past Due [Member] | Multifamily real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	91	317
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	0
30 to 59 Days Past Due [Member] | One- to four-family construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	4,781
30 to 59 Days Past Due [Member] | Land and land development - residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	450
30 to 59 Days Past Due [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	34
30 to 59 Days Past Due [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	8,982	3,982
30 to 59 Days Past Due [Member] | Agricultural business, including secured by farmland [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	131	343
30 to 59 Days Past Due [Member] | One- to four-family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	826	5,440
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	1,324	1,136
30 to 59 Days Past Due [Member] | Consumer - other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	558	911
60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,496	7,858
60 to 89 Days Past Due [Member] | Commerical real estate - owner-occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	146	519
60 to 89 Days Past Due [Member] | Commercial real estate - investment properties [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	498
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	0
60 to 89 Days Past Due [Member] | One- to four-family construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,454	1,078
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	0
60 to 89 Days Past Due [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	895	1,305
60 to 89 Days Past Due [Member] | Agricultural business, including secured by farmland [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	30	1,518
60 to 89 Days Past Due [Member] | One- to four-family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,496	1,790
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	346	765
60 to 89 Days Past Due [Member] | Consumer - other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	129	385
90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	15,839	12,074
90 Days or More Past Due [Member] | Commerical real estate - owner-occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,474	2,223
90 Days or More Past Due [Member] | Commercial real estate - investment properties [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,612	934
90 Days or More Past Due [Member] | Multifamily real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
90 Days or More Past Due [Member] | Commercial construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	605	1,427
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	1,181	919
90 Days or More Past Due [Member] | Land and land development - residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	690	798
90 Days or More Past Due [Member] | Land and land development - commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	44
90 Days or More Past Due [Member] | Commercial business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,211	1,756
90 Days or More Past Due [Member] | Agricultural business, including secured by farmland [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,359	1,601
90 Days or More Past Due [Member] | One- to four-family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,219	1,657
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	2,233	706
90 Days or More Past Due [Member] | Consumer - other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 255	$ 9

LOANS RECEIVABLE AND THE ALL_11

LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Allowance for Loan Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, Beginning balance	$ 97,308	$ 92,207	$ 96,485	$ 89,028
Provision for loan losses	2,000	2,000	4,000	4,000
Recoveries	882	830	1,101	2,928
Charge-offs	(1,936)	(1,162)	(3,332)	(2,081)
Allowance for loan losses, Ending balance	98,254	93,875	98,254	93,875
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment					$ 297		$ 468
Allowance collectively evaluated for impairment					97,877		93,314
Allowance for purchased credit-impaired loans					80		93
Total allowance for loan losses	97,308	92,207	96,485	89,028	98,254	$ 96,485	93,875
Loans individually evaluated for impairment					14,672		18,409
Loans collectively evaluated for impairment					8,718,933		7,648,260
Purchased Credit-Impaired					12,945	14,413	18,063
Total loans					8,746,550	8,684,595	7,684,732
Commercial real estate [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, Beginning balance	27,091	23,461	27,132	22,824
Provision for loan losses	(117)	1,035	252	320
Recoveries	149	216	170	1,568
Charge-offs	(393)	(299)	(824)	(299)
Allowance for loan losses, Ending balance	26,730	24,413	26,730	24,413
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment					64		278
Allowance collectively evaluated for impairment					26,666		24,135
Allowance for purchased credit-impaired loans					0		0
Total allowance for loan losses	27,091	23,461	27,132	22,824	26,730	27,132	24,413
Loans individually evaluated for impairment					4,352		8,998
Loans collectively evaluated for impairment					3,534,235		3,155,917
Purchased Credit-Impaired					11,714		12,605
Total loans					3,550,301		3,177,520
Multifamily real estate [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, Beginning balance	4,020	2,592	3,818	1,633
Provision for loan losses	324	1,126	526	2,085
Recoveries	0	0	0	0
Charge-offs	0	0	0	0
Allowance for loan losses, Ending balance	4,344	3,718	4,344	3,718
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment					0		0
Allowance collectively evaluated for impairment					4,344		3,718
Allowance for purchased credit-impaired loans					0		0
Total allowance for loan losses	4,020	2,592	3,818	3,718	4,344	3,818	3,718
Loans individually evaluated for impairment					0		0
Loans collectively evaluated for impairment					402,235		330,220
Purchased Credit-Impaired					6	138	164
Total loans					402,241	368,836	330,384
Construction and Land [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, Beginning balance	23,713	28,766	24,442	27,568
Provision for loan losses	(189)	(1,743)	(940)	(719)
Recoveries	30	11	52	185
Charge-offs	0	0	0	0
Allowance for loan losses, Ending balance	23,554	27,034	23,554	27,034
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment					0		0
Allowance collectively evaluated for impairment					23,554		27,034
Allowance for purchased credit-impaired loans					0		0
Total allowance for loan losses	23,713	28,766	24,442	27,568	23,554	24,442	27,034
Loans individually evaluated for impairment					2,166		750
Loans collectively evaluated for impairment					1,077,636		976,435
Purchased Credit-Impaired					0		3,255
Total loans					1,079,802		980,440
Commercial business [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, Beginning balance	18,662	19,885	19,438	18,311
Provision for loan losses	1,482	(469)	1,273	1,454
Recoveries	215	100	238	270
Charge-offs	(802)	(375)	(1,392)	(894)
Allowance for loan losses, Ending balance	19,557	19,141	19,557	19,141
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment					21		13
Allowance collectively evaluated for impairment					19,513		19,095
Allowance for purchased credit-impaired loans					23		33
Total allowance for loan losses	18,662	19,885	19,557	18,311	19,557	19,438	19,141
Loans individually evaluated for impairment					550		369
Loans collectively evaluated for impairment					1,597,712		1,310,601
Purchased Credit-Impaired					526	1,028	1,454
Total loans					1,598,788	1,483,614	1,312,424
Agricultural Business/Farmland [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, Beginning balance	3,596	2,999	3,778	4,053
Provision for loan losses	222	451	44	(596)
Recoveries	35	41	35	41
Charge-offs	(162)	(329)	(166)	(336)
Allowance for loan losses, Ending balance	3,691	3,162	3,691	3,162
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment					147		59
Allowance collectively evaluated for impairment					3,487		3,043
Allowance for purchased credit-impaired loans					57		60
Total allowance for loan losses	3,596	2,999	3,778	4,053	3,691	3,778	3,162
Loans individually evaluated for impairment					3,058		3,298
Loans collectively evaluated for impairment					377,333		333,015
Purchased Credit-Impaired					414	493	396
Total loans					380,805	404,873	336,709
One- to four-family [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, Beginning balance	4,711	3,779	4,714	2,055
Provision for loan losses	(240)	(203)	(286)	1,247
Recoveries	230	356	273	646
Charge-offs	0	0	0	(16)
Allowance for loan losses, Ending balance	4,701	3,932	4,701	3,932
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment					58		108
Allowance collectively evaluated for impairment					4,643		3,824
Allowance for purchased credit-impaired loans					0		0
Total allowance for loan losses	4,711	3,779	4,714	3,932	4,701	4,714	3,932
Loans individually evaluated for impairment					3,582		4,789
Loans collectively evaluated for impairment					940,948		835,560
Purchased Credit-Impaired					87	101	121
Total loans					944,617	973,616	840,470
Consumer [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, Beginning balance	7,980	5,514	7,972	3,866
Provision for loan losses	828	264	1,097	2,177
Recoveries	223	106	333	218
Charge-offs	(579)	(159)	(950)	(536)
Allowance for loan losses, Ending balance	8,452	5,725	8,452	5,725
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment					7		10
Allowance collectively evaluated for impairment					8,445		5,715
Allowance for purchased credit-impaired loans					0		0
Total allowance for loan losses	7,980	5,514	7,972	3,866	8,452	7,972	5,725
Loans individually evaluated for impairment					964		205
Loans collectively evaluated for impairment					788,834		706,512
Purchased Credit-Impaired					198		68
Total loans					789,996		706,785
Unallocated Financing Receivables [Member]
Financing Receivable, Allowance for Loan Losses [Roll Forward]
Allowance for loan losses, Beginning balance	7,535	5,211	5,191	8,718
Provision for loan losses	(310)	1,539	2,034	(1,968)
Recoveries	0	0	0	0
Charge-offs	0	0	0	0
Allowance for loan losses, Ending balance	7,225	6,750	7,225	6,750
Financing Receivable, Allowance for Loan Losses, Additional Information [Abstract]
Allowance individually evaluated for impairment					0		0
Allowance collectively evaluated for impairment					7,225		6,750
Allowance for purchased credit-impaired loans					0		0
Total allowance for loan losses	$ 7,535	$ 5,211	$ 5,191	$ 8,718	7,225	$ 5,191	6,750
Loans individually evaluated for impairment					0		0
Loans collectively evaluated for impairment					0		0
Purchased Credit-Impaired					0		0
Total loans					$ 0		$ 0

GOODWILL, OTHER INTANGIBLE AS_3

GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Finite-Lived Intangible Assets) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 339,154	$ 242,659
Goodwill, Acquired During Period		96,495
Goodwill, end of period	339,154	339,154
Finite-lived Intangible Assets [Roll Forward]
Goodwill and other intangibles, net, beginning of period	372,078	265,314
Additions through acquisitions		112,863
Amortization	(4,112)	(6,099)
Goodwill adjustments	(217)
Goodwill and other intangibles, net, end of period	367,749	372,078
Core Deposit Intangibles [Member]
Finite-lived Intangible Assets [Roll Forward]
Finite lived assets Balance, beginning of period	32,699	22,378
Intangible assets, additions through acquisitions		16,368
Amortization	(4,104)	(6,047)
Finite lived assets Balance, end of period	28,595	32,699
Leasehold Improvements [Member]
Finite-lived Intangible Assets [Roll Forward]
Finite lived assets Balance, beginning of period	225	277
Intangible assets, additions through acquisitions		0
Amortization	(8)	(52)
Goodwill adjustments	(217)
Finite lived assets Balance, end of period	$ 0	$ 225

REAL ESTATE OWNED, NET (REO Rol

REAL ESTATE OWNED, NET (REO Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Real Estate [Abstract]
Proceeds from Sale of Other Real Estate	$ 150	$ 314	$ 150	$ 314
Gains (Losses) on Sales of Other Real Estate	9	(66)	9	(66)
Real Estate Owned [Roll Forward]
Balance, beginning of the period	2,611	328	2,611	360
Additions from loan foreclosures	61	393	61	521
Valuation adjustments in the period	0	0	0	(160)
Balance, end of the period	$ 2,513	$ 473	$ 2,513	$ 473

GOODWILL, OTHER INTANGIBLE AS_4

GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Estimated Annual Amortization Expense) (Details) - Core Deposit Intangibles [Member] - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Remainder of 2017	$ 3,853
2018	6,888
2019	5,816
2020	4,651
2021	3,237
Thereafter	4,150
Finite lived assets, net	$ 28,595	$ 32,699	$ 22,378

REAL ESTATE OWNED, NET REAL EST

REAL ESTATE OWNED, NET REAL ESTATE OWNED, NET (Textual) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Real Estate Owned [Line Items]
Real Estate Owned	$ 2,513	$ 2,611	$ 2,611	$ 473	$ 328	$ 360
Mortgage Loans in Process of Foreclosure, Amount	1,800		$ 1,200
One- to four-family residential [Member]
Real Estate Owned [Line Items]
Real Estate Owned	$ 61

GOODWILL, OTHER INTANGIBLE AS_5

GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Mortgage Servicing Rights) (Details) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
		Jun. 30, 2019		Jun. 30, 2018		Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Servicing Asset at Amortized Value, Balance [Roll Forward]
Servicing Asset at Amortized Cost, Additions, Acquisitions		$ 22		$ 30
Servicing Asset at Amortized Cost, Additions						$ 69	$ 45
ERROR in label resolution.
Morgage Servicing Rights at Amortized Value [Line Items]
Loans Serviced For Others		2,390,000				2,390,000		$ 2,360,000
Custodial Accounts		16,000				16,000		$ 11,100
Servicing Asset at Amortized Value, Balance [Roll Forward]
Balance, net of valuation allowance, beginning of the period		14,417		14,617		14,638	14,738
Additions—amounts capitalized		685		863		1,357	1,684
Amortization		(1,126)	[1]	(989)	[1]	(2,066)	(1,946)
Balance, net of valuation allowance, end of the period	[2]	13,998		$ 14,521		13,998	$ 14,521
Valuation allowance, end of period		$ 0				$ 0
[1]	Amortization of mortgage servicing rights is recorded as a reduction of loan servicing income within mortgage banking operations and any unamortized balance is fully amortized if the loan repays in full.
[2]	There was no valuation allowance as of June 30, 2019 and 2018 .

DEPOSITS (Deposit Liabilities)

DEPOSITS (Deposit Liabilities) (Details) - USD ($)		Jun. 30, 2019	Dec. 31, 2018
Deposits:
Non-interest-bearing accounts		$ 3,671,995,000	$ 3,657,817,000
Interest-bearing checking		1,187,035,000	1,191,016,000
Regular savings accounts		1,848,048,000	1,842,581,000
Money market accounts		1,511,119,000	1,465,369,000
Total interest-bearing transaction and saving accounts		4,546,202,000	4,498,966,000
Certificates of deposit less than or equal to $250,000		891,312,000	1,143,303,000
Certificates of deposit greater than $250,000		179,458,000	176,962,000
Total certificates of deposit	[1]	1,070,770,000	1,320,265,000
Total deposits		9,288,967,000	9,477,048,000
Included in total deposits:
Public fund transaction and savings accounts		223,610,000	217,401,000
Public fund interest-bearing certificates		28,656,000	30,089,000
Total public deposits		252,266,000	247,490,000
Total brokered deposits		138,395,000	377,347,000
CD acquisition premium		$ 384,000	$ 563,000
[1]	Certificates of deposit include $384,000 and $563,000 of acquisition premiums at June 30, 2019 and December 31, 2018 , respectively.

DEPOSITS DEPOSITS (Maturities a

DEPOSITS DEPOSITS (Maturities and Weighted Average Interest Rates of Certificates of Deposit) (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
Maturities of Time Deposits [Abstract]
Maturing in one year or less		$ 766,901
Maturing after one year through two years		196,538
Maturing after two years through three years		81,540
Maturing after three years through four years		12,620
Maturing after four years through five years		10,778
Maturing after five years		2,393
Total certificates of deposit	[1]	$ 1,070,770	$ 1,320,265
Weighted Average Rate [Abstract]
Maturing in one year or less		1.14%
Maturing after one year through two years		1.65%
Maturing after two years through three years		1.87%
Maturing after three years through four years		1.45%
Maturing after four years through five years		2.24%
Maturing after five years		1.14%
Total certificates of deposit		1.31%
[1]	Certificates of deposit include $384,000 and $563,000 of acquisition premiums at June 30, 2019 and December 31, 2018 , respectively.

DEPOSITS DEPOSITS (Textual) (De

DEPOSITS DEPOSITS (Textual) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Banking and Thrift [Abstract]
Time Deposits, at or Above FDIC Insurance Limit	$ 184.5	$ 180.5

FAIR VALUE OF FINANCIAL INSTR_3

FAIR VALUE OF FINANCIAL INSTRUMENTS (Fair Value By Balance Sheet Location) (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Assets:
Securities—trading	$ 25,741,000	$ 25,896,000
Securities—available-for-sale	1,561,009,000	1,636,223,000
Securities—held-to-maturity	206,917,000	232,537,000
Liabilities:
FHLB advances at fair value	606,000,000	540,189,000
Carrying Value
Assets:
Cash and cash equivalents	187,043,000	272,196,000
Securities—trading	25,741,000	25,896,000
Securities—available-for-sale	1,561,009,000	1,636,223,000
Loans receivable held for sale	170,744,000	171,031,000
Loans receivable	8,746,550,000	8,684,595,000
FHLB stock	34,583,000	31,955,000
Bank-owned life insurance	178,922,000	177,467,000
Mortgage servicing rights	13,998,000	14,638,000
Equity Securities, FV-NI	0
Liabilities:
Demand, interest checking and money market accounts	6,370,149,000	6,314,202,000
Regular savings	1,848,048,000	1,842,581,000
Certificates of deposit	1,070,770,000	1,320,265,000
FHLB advances at fair value	606,000,000	540,189,000
Other borrowings	118,370,000	118,995,000
Junior subordinated debentures at fair value	113,621,000	114,091,000
Estimated Fair Value
Assets:
Cash and cash equivalents	187,043,000	272,196,000
Securities—trading	25,741,000	25,896,000
Securities—available-for-sale	1,561,009,000	1,636,223,000
Loans receivable held for sale	171,385,000	171,157,000
Loans receivable	8,804,689,000	8,629,450,000
FHLB stock	34,583,000	31,955,000
Bank-owned life insurance	178,922,000	177,467,000
Mortgage servicing rights	22,030,000	25,813,000
Equity Securities, FV-NI	0
Liabilities:
Demand, interest checking and money market accounts	6,370,149,000	6,314,202,000
Regular savings	1,848,048,000	1,842,581,000
Certificates of deposit	1,065,200,000	1,298,238,000
FHLB advances at fair value	609,464,000	540,189,000
Other borrowings	118,370,000	118,995,000
Junior subordinated debentures at fair value	113,621,000	114,091,000
Interest rate swaps [Member] | Carrying Value
Assets:
Derivatives:	13,604,000	3,138,000
Liabilities:
Derivatives:	11,067,000	3,138,000
Interest rate swaps [Member] | Estimated Fair Value
Assets:
Derivatives:	13,604,000	3,138,000
Liabilities:
Derivatives:	11,067,000	3,138,000
Interest Rate Forward Sales Commitments [Member] | Carrying Value
Assets:
Derivatives:	1,545,000	471,000
Liabilities:
Derivatives:	1,080,000	1,654,000
Interest Rate Forward Sales Commitments [Member] | Estimated Fair Value
Assets:
Derivatives:	1,545,000	471,000
Liabilities:
Derivatives:	1,080,000	1,654,000
Fair Value, Inputs, Level 2 [Member] | Carrying Value
Assets:
Securities—held-to-maturity	200,054,000	230,984,000
Fair Value, Inputs, Level 2 [Member] | Estimated Fair Value
Assets:
Securities—held-to-maturity	203,749,000	229,301,000
Fair Value, Inputs, Level 3 [Member] | Carrying Value
Assets:
Securities—held-to-maturity	3,168,000	3,236,000
Fair Value, Inputs, Level 3 [Member] | Estimated Fair Value
Assets:
Securities—held-to-maturity	$ 3,168,000	$ 3,236,000

FAIR VALUE OF FINANCIAL INSTR_4

FAIR VALUE OF FINANCIAL INSTRUMENTS (Assets and Liabilities Measured on a Recurring Basis) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	$ 25,741	$ 25,896
Securities—available-for-sale	1,561,009	1,636,223
Advances from FHLB	606,000	540,189
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	25,741	25,896
Securities—available-for-sale	1,561,009	1,636,223
Total assets	1,751,590	1,830,847
Junior subordinated debentures net of unamortized deferred issuance costs at fair value	113,621	114,091
Total liabilities	125,768	118,883
Recurring [Member] | Interest rate lock and forward sale commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1,545	3,138
Derivative liabilities	1,080	3,138
Recurring [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	13,604	471
Derivative liabilities	11,067	1,654
Recurring [Member] | U.S. Government and agency obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	125,068	149,112
Recurring [Member] | Municipal bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	110,910	117,822
Recurring [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	4,561	3,495
Recurring [Member] | TPS and TRUP CDOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	25,741	25,896
Recurring [Member] | Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	1,312,433	1,343,861
Recurring [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	8,037	21,933
Recurring [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	149,691	164,767
Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	0	0
Securities—available-for-sale	0	0
Total assets	0	0
Junior subordinated debentures net of unamortized deferred issuance costs at fair value	0	0
Total liabilities	0	0
Recurring [Member] | Level 1 [Member] | Interest rate lock and forward sale commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Recurring [Member] | Level 1 [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Recurring [Member] | Level 1 [Member] | U.S. Government and agency obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	0	0
Recurring [Member] | Level 1 [Member] | Municipal bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	0	0
Recurring [Member] | Level 1 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	0	0
Recurring [Member] | Level 1 [Member] | TPS and TRUP CDOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	0	0
Recurring [Member] | Level 1 [Member] | Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	0	0
Recurring [Member] | Level 1 [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	0	0
Recurring [Member] | Level 1 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	0	0
Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	0	0
Securities—available-for-sale	1,561,009	1,636,223
Total assets	1,725,849	1,804,951
Junior subordinated debentures net of unamortized deferred issuance costs at fair value	0	0
Total liabilities	12,147	4,792
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest rate lock and forward sale commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1,545	3,138
Derivative liabilities	1,080	3,138
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	13,604	471
Derivative liabilities	11,067	1,654
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government and agency obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	125,068	149,112
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	110,910	117,822
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	4,561	3,495
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | TPS and TRUP CDOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	0	0
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	1,312,433	1,343,861
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	8,037	21,933
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	149,691	164,767
Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	25,741	25,896
Securities—available-for-sale	0	0
Total assets	25,741	25,896
Junior subordinated debentures net of unamortized deferred issuance costs at fair value	113,621	114,091
Total liabilities	113,621	114,091
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest rate lock and forward sale commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and agency obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | TPS and TRUP CDOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	25,741	25,896
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	$ 0	$ 0

FAIR VALUE OF FINANCIAL INSTR_5

FAIR VALUE OF FINANCIAL INSTRUMENTS (Valuation Technique) (Details) - Fair Value, Inputs, Level 3 [Member]	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Junior Subordinated Debt [Member] | Discounted cash flows [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate, Description of Variable Rate Basis	three-month LIBOR
Fair Value Inputs, Discount Rate, Basis Spread on Variable Rate Basis	4.00%	4.00%
Corporate Bonds (TPS securities) [Member] | Weighted Average [Member] | Discounted cash flows [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value Input, Discount Rate		6.32%	6.81%
Impaired Loans [Member] | Minimum [Member] | discount to appraised value [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
fair value inputs, discount to appraised value		8.50%	0.00%
Impaired Loans [Member] | Maximum [Member] | discount to appraised value [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
fair value inputs, discount to appraised value		9.00%	8.50%
Real Estate Owned [Member] | Weighted Average [Member] | discount to appraised value [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
fair value inputs, discount to appraised value		32.00%	69.20%

FAIR VALUE OF FINANCIAL INSTR_6

FAIR VALUE OF FINANCIAL INSTRUMENTS (Unobservable Inputs Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Junior Subordinated Debt [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 113,917	$ 112,516	$ 114,091	$ 98,707
Liabilities (gains) losses	(296)	258	(470)	14,067
Ending balance	113,621	112,774	113,621	112,774
TPS Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	25,838	25,474
Assets gains (losses), including OTTI	(97)	66
Ending balance	25,741	25,540	25,741	25,540
TPS and TRUP CDOs [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance			25,896	22,058
Assets gains (losses), including OTTI			(155)	3,482
Ending balance	$ 25,741	$ 25,540	$ 25,741	$ 25,540

FAIR VALUE OF FINANCIAL INSTR_7

FAIR VALUE OF FINANCIAL INSTRUMENTS (Assets Measured on Nonrecurring Basis) (Details) - Nonrecurring [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ (1,225)		$ (1,225)		$ (2,915)
REO	2,513		2,513		2,611
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0		0		0
REO	0		0		0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0		0		0
REO	0		0		0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	(1,225)		(1,225)		(2,915)
REO	2,513		2,513		$ 2,611
Gains (losses) resulting from nonrecurring fair value adjustments	(125)	$ (329)	(425)	$ (489)
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) resulting from nonrecurring fair value adjustments	(125)	(329)	(425)	(329)
Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) resulting from nonrecurring fair value adjustments	$ 0	$ 0	$ 0	$ (160)

INCOME TAXES AND DEFERRED TAX_3

INCOME TAXES AND DEFERRED TAXES INCOME TAXES AND DEFERRED TAXES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Tax credit investments	$ 21,359		$ 21,359		$ 17,360
Unfunded commitments—tax credit investments	15,700		15,700		$ 12,726
Tax credits and other tax benefits recognized	494	$ 364	988	$ 728
Tax credit amortization expense included in provision for income taxes	$ 405	$ 288	$ 810	$ 575

CALCULATION OF WEIGHTED AVERA_3

CALCULATION OF WEIGHTED AVERAGE SHARES OUTSTANDING FOR EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net income	$ 39,700	$ 33,346	$ 37,527	$ 37,773	$ 32,424	$ 28,790	$ 73,046	$ 61,214
Basic weighted average shares outstanding	34,831,047				32,250,514		34,940,106	32,323,635
Plus unvested restricted stock	51,312				81,095		88,775	98,652
Diluted weighted shares outstanding	34,882,359				32,331,609		35,028,881	32,422,287
Earnings per common share
Basic	$ 1.14				$ 1.01		$ 2.09	$ 1.89
Diluted	$ 1.14				$ 1		$ 2.09	$ 1.89

STOCK-BASED COMPENSATION PLANS

STOCK-BASED COMPENSATION PLANS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		62 Months Ended	86 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2019
Restricted Stock Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Expense	$ 2.2	$ 1.9		$ 3.3
Compensation Cost Not yet Recognized	$ 15.9		$ 15.9		$ 15.9	$ 15.9
Compensation Cost Not yet Recognized, Period for Recognition			36 months
2012 Restricted Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Authorized	300,000		300,000		300,000	300,000
2012 Restricted Stock Plan [Member] | Restricted Stock Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award Vesting Period			3 years
Award Expiration Period			10 years
Restricted stock granted						269,863
Restricted stock grants, shares vested						261,966
Restricted stock grants, shares non-vested	7,897		7,897		7,897	7,897
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	900,000
2014 Omnibus Incentive Plan [Member] | Restricted Stock Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted					316,281
Restricted stock grants, shares vested					281,760
2014 Omnibus Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted					384,117
Restricted stock grants, shares vested					52,371
2018 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	900,000
2018 Omnibus Incentive Plan [Member] | Restricted Stock Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted			0

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES (Commitments Without Recorded Liability) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Reserve for Unfunded Loan Commitments	$ 2,600,000
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
ERROR in label resolution.
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount	$ 2,934,838,000		$ 2,837,981,000
ERROR in label resolution.
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount	15,529,000		17,784,000
ERROR in label resolution.
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount	61,037,000		32,145,000
ERROR in label resolution.
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount	41,057,000		24,091,000
ERROR in label resolution.
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount	110,648,000		31,728,000
ERROR in label resolution.
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount	46,726,000		18,328,000
Counterparty default losses on forward contracts	0	$ 0
ERROR in label resolution.
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contract or Notional Amount	225,703,000		$ 144,250,000
Counterparty default losses on forward contracts	$ 0	$ 0

DERIVATIVES AND HEDGING (Deriva

DERIVATIVES AND HEDGING (Derivatives Designated as Hedging, by Balance Sheet Location) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	$ 13,621	$ 5,038
Liability Derivatives, Fair Value	13,621	5,038
Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	13,621	5,038
Liability Derivatives, Fair Value	13,621	5,038
Interest rate swaps [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional/Contract Amount	3,773	3,973
Liability Derivatives, Notional/Contract Amount	3,773	3,973
Interest rate swaps [Member] | Designated as Hedging Instrument [Member] | Loans Receivable [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	279	270
Interest rate swaps [Member] | Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Fair Value	$ 279	$ 270

DERIVATIVES AND HEDGING (Deri_2

DERIVATIVES AND HEDGING (Derivatives Not Designated as Hedging, by Balance Sheet Location) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	$ 13,621	$ 5,038
Liability Derivatives, Fair Value	13,621	5,038
Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	13,621	5,038
Liability Derivatives, Fair Value	13,621	5,038
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional/Contract Amount	422,952	310,931
Liability Derivatives, Notional/Contract Amount	556,009	434,387
Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	14,870	3,339
Not Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Fair Value	11,868	4,522
Not Designated as Hedging Instrument [Member] | Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional/Contract Amount	287,416	272,374
Liability Derivatives, Notional/Contract Amount	287,416	272,374
Not Designated as Hedging Instrument [Member] | Interest rate swaps [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	13,325	2,868
Not Designated as Hedging Instrument [Member] | Interest rate swaps [Member] | Loans Receivable [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	406	282
Not Designated as Hedging Instrument [Member] | Interest rate swaps [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Fair Value	10,788	2,868
Not Designated as Hedging Instrument [Member] | Mortgage loan commitments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional/Contract Amount	88,810	20,229
Liability Derivatives, Notional/Contract Amount	42,890	17,763
Not Designated as Hedging Instrument [Member] | Mortgage loan commitments [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	1,373	273
Not Designated as Hedging Instrument [Member] | Mortgage loan commitments [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Fair Value	45	187
Not Designated as Hedging Instrument [Member] | Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional/Contract Amount	46,726	18,328
Liability Derivatives, Notional/Contract Amount	225,703	144,250
Not Designated as Hedging Instrument [Member] | Forward Contracts [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	172	198
Not Designated as Hedging Instrument [Member] | Forward Contracts [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Fair Value	$ 1,035	$ 1,467

DERIVATIVES AND HEDGING (Gain (

DERIVATIVES AND HEDGING (Gain (Loss) On Derivatives Not Designated in Hedging Relationship) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in income, net	$ 701	$ 23	$ 858	$ 432
Mortgage loan commitments [Member] | Mortgage banking operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in income, net	1,093	96	1,100	164
Forward sales contracts [Member] | Mortgage banking operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in income, net	$ (392)	$ (73)	$ (242)	$ 268

DERIVATIVES AND HEDGING (Narrat

DERIVATIVES AND HEDGING (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative net liability position	$ 13.6	$ 1.3
Collateral posted	$ 20.7	$ 13.6

DERIVATIVES AND HEDGING (Deri_3

DERIVATIVES AND HEDGING (Derivative Offsetting) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Offsetting Derivative Assets [Abstract]
Derivative Assets, Gross Amounts Recognized	$ 13,621	$ 5,038
Derivative Assets, Amounts offsett in the Statement of Financial Condition	(17)	(1,900)
Derivative Assets, Net Amounts in the Statement of Financial Condition	13,604	3,138
Derivative Assets, Netting Adjustment Per Applicable Master Netting Agreements	0	0
Derivative Assets, Fair Value of Financial Collateral in the Statement of Financial Condiation	0	0
Derivative Assets, Net Amount	13,604	3,138
Offsetting Derivative Liabilities [Abstract]
Derivative Liabilities, Gross Amounts Recognized	13,621	5,038
Derivative Liabilities, Amounts offset in the Statement of Financial Condition	(2,554)	(1,900)
Derivative Liabilities, Net Amounts of the Statement of Financial Condition	11,067	3,138
Derivative Liabilities, Net Adjustment Per Applicable Master Netting Agreements	0	0
Derivative Liabilities, Fair Value of Financial Collateral in the Statement of Financial Condition	(10,919)	(1,320)
Derivative Liabilities, Net Amount	148	1,818
Interest rate swaps [Member]
Offsetting Derivative Assets [Abstract]
Derivative Assets, Gross Amounts Recognized	13,621	5,038
Derivative Assets, Amounts offsett in the Statement of Financial Condition	(17)	(1,900)
Derivative Assets, Net Amounts in the Statement of Financial Condition	13,604	3,138
Derivative Assets, Netting Adjustment Per Applicable Master Netting Agreements	0	0
Derivative Assets, Fair Value of Financial Collateral in the Statement of Financial Condiation	0	0
Derivative Assets, Net Amount	13,604	3,138
Offsetting Derivative Liabilities [Abstract]
Derivative Liabilities, Gross Amounts Recognized	13,621	5,038
Derivative Liabilities, Amounts offset in the Statement of Financial Condition	(2,554)	(1,900)
Derivative Liabilities, Net Amounts of the Statement of Financial Condition	11,067	3,138
Derivative Liabilities, Net Adjustment Per Applicable Master Netting Agreements	0	0
Derivative Liabilities, Fair Value of Financial Collateral in the Statement of Financial Condition	(10,919)	(1,320)
Derivative Liabilities, Net Amount	$ 148	$ 1,818

REVENUE FROM CONTRACTS WITH C_3

REVENUE FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Debit And Credit Card Interchange Fees	$ 9,272	$ 7,872	$ 17,203	$ 15,191
Debit and Credit Card Expense	(1,949)	(1,933)	(4,398)	(3,903)
Merchant Services Expenses	(2,661)	(1,924)	(4,981)	(3,729)
Other Service Charges	1,210	929	3,223	2,100
Total Deposit Fees and Other Service Charges	14,046	11,985	26,664	23,281
Deposit Account [Member]
Disaggregation of Revenue [Line Items]
Mortgage banking operations	4,829	4,528	9,416	8,848
Credit Card, Merchant Discount [Member]
Disaggregation of Revenue [Line Items]
Mortgage banking operations	$ 3,345	$ 2,513	$ 6,201	$ 4,774

LEASES (Details)

LEASES (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)office
Leases [Abstract]
Number of buildings and offices under operating leases | office		106
Operating right-of-use lease assets	$ 54,515	$ 54,515
Operating lease liabilities	$ 57,638	$ 57,638
Weighted-average remaining lease term: Operating leases	5 years 9 months 18 days	5 years 9 months 18 days
Weighted-average discount rate: Operating leases	4.24%	4.24%
Operating lease cost	$ 3,858	$ 7,832
Short-term lease costs	99	222
Variable lease cost	567	1,128
Less sublease income	(231)	(468)
Total lease cost	4,293	8,714
Operating cash flows paid for operating lease amounts	3,800	7,700
Right-of-use assets in exchange for operating lease liabilities	2,900	64,100
Operating Lease Liabilities, Payments Due [Abstract]
Remainder of 2019	7,514	7,514
2020	14,330	14,330
2021	12,611	12,611
2022	9,083	9,083
2023	6,011	6,011
Thereafter	15,659	15,659
Total minimum lease payments	65,208	65,208
Less: amount of lease payments representing interest	(7,570)	(7,570)
Operating lease liabilities	$ 57,638	57,638
Undiscounted lease payments under an operating lease that had not yet commenced		$ 2,800
Lease not yet commenced, lease term	20 years	20 years

SUBSEQUENT EVENT (Details)

SUBSEQUENT EVENT (Details) - AltaPacific Bank [Member] - Subsequent Event [Member] $ / shares in Units, $ in Millions	Jul. 24, 2019USD ($)$ / sharesshares
Subsequent Event [Line Items]
Business Combination, Combined Assets	$ 12,200
Subsequent Event, Date	Jul. 24, 2019
Business Combination, Consideration Transferred, Equity Interest Issued And Issuable, Shares | shares	0.2712
Business Combination, Consideration Transfered, Per Share Value | $ / shares	$ 54.19
Business Combination, consideration transfered	$ 87.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	436
Loans receivable (contractual amount of $645.6 million)	339
Deposits	$ 307
Southern California [Member]
Subsequent Event [Line Items]
Business Combination, Number Of Branches Acquired	5
Northern California [Member]
Subsequent Event [Line Items]
Business Combination, Number Of Branches Acquired	1