LOANS (Schedule of Balances by Portfolio Class, Based on Impairment Method) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Total Loans Individually Evaluated for Impairment	$ 23,065	$ 29,071
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	522	824
Total Loans Collectively Evaluated for Impairment	3,679,467	3,281,033
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	35,918	31,384
Total Loans	3,702,532	3,310,104
Total Ending ALLL	36,440	32,208	$ 25,856	$ 19,480
Residential Portfolio Segment [Member] \| Junior Lien [Member]
Total Loans Individually Evaluated for Impairment	52	229
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	7,021	8,977
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	12	16
Total Loans	7,073	9,206
Total Ending ALLL	12	16	66	109
Consumer and Other [Member]
Total Loans Individually Evaluated for Impairment
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	92	73,621
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	1	243
Total Loans	99,247	73,621
Total Ending ALLL	349	243	112	96
Primary Residential Mortgages [Member] \| Residential Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	9,802	15,814
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	482	456
Total Loans Collectively Evaluated for Impairment	595,767	542,156
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	3,603	3,210
Total Loans	605,569	557,970
Total Ending ALLL	4,085	3,666	2,297	2,923
Home Equity Lines of Credit [Member] \| Residential Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	27	53
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	67,470	65,630
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	221	233
Total Loans	67,497	65,683
Total Ending ALLL	221	233	86	156
Multifamily Property [Member] \| Residential Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	1,388,958	1,459,594
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	10,007	11,192
Total Loans	1,388,958	1,459,594
Total Ending ALLL	10,007	11,192	11,813	8,983
Owner Occupied Property [Member] \| Commercial Real Estate Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	2,503	1,486
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	250,989	174,637
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	2,385	1,774
Total Loans	253,492	176,123
Total Ending ALLL	2,385	1,774	1,679	1,547
Investment Property [Member] \| Commercial Real Estate Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	10,681	11,335
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	40	214
Total Loans Collectively Evaluated for Impairment	863,417	740,923
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	11,893	10,695
Total Loans	874,098	752,258
Total Ending ALLL	11,933	10,909	7,590	4,751
Construction Loans [Member] \| Commercial Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	160	1,497
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment		9
Total Loans	92	1,497
Total Ending ALLL	1	9	2	31
Commercial and Industrial Sector [Member] \| Commercial Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment		154
Ending ALLL Attributable to Loans Individually Evaluated for Impairment		154
Total Loans Collectively Evaluated for Impairment	316,294	213,829
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	6,563	4,010
Total Loans	316,294	213,983
Total Ending ALLL	6,563	4,164	2,209	880
Agricultural Sector [Member]
Total Loans Individually Evaluated for Impairment
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	90,052	169
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	884	2
Total Loans	160	169
Total Ending ALLL		$ 2	$ 2	$ 4

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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