LOANS (Schedule of Balances by Portfolio Class, Based on Impairment Method) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Total Loans Individually Evaluated for Impairment	$ 23,335	$ 23,107
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	491	490
Total Loans Collectively Evaluated for Impairment	3,002,502	2,888,445
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	26,830	25,366
Total Loans	3,025,837	2,911,552
Total Ending ALLL	$ 27,321	$ 25,856	$ 20,816	$ 19,480
Agricultural Sector [Member]
Total Loans Individually Evaluated for Impairment
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	$ 177	$ 179
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	2	2
Total Loans	177	179
Total Ending ALLL	2	2	3	4
Residential Portfolio Segment [Member] \| Junior Lien [Member]
Total Loans Individually Evaluated for Impairment	$ 171	$ 176
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	$ 10,515	$ 11,327
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	13	66
Total Loans	10,686	11,503
Total Ending ALLL	13	66	71	109
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member]
Total Loans Individually Evaluated for Impairment	136	171
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	136	138
Total Loans Collectively Evaluated for Impairment	173,163	154,124
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	2,555	2,071
Total Loans	173,299	154,295
Total Ending ALLL	$ 2,691	$ 2,209	1,011	880
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	$ 47,894	$ 47,635
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	136	112
Total Loans	47,894	47,635
Total Ending ALLL	136	112	77	96
Primary Residential Mortgages [Member] \| Residential Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	10,165	9,752
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	297	291
Total Loans Collectively Evaluated for Impairment	489,569	473,333
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	2,206	2,006
Total Loans	499,734	483,085
Total Ending ALLL	2,503	2,297	2,314	2,923
Home Equity Lines of Credit [Member] \| Residential Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	$ 153	$ 254
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	$ 53,328	$ 52,550
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	133	86
Total Loans	53,481	52,804
Total Ending ALLL	$ 133	$ 86	97	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	$ 1,489,708	$ 1,416,775
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	11,631	11,813
Total Loans	1,489,708	1,416,775
Total Ending ALLL	11,631	11,813	8,738	8,983
Owner Occupied Property [Member] \| Commercial Real Estate Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	$ 1,264	$ 1,272
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	$ 162,231	$ 175,004
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	1,683	1,679
Total Loans	163,495	176,276
Total Ending ALLL	1,683	1,679	2,347	1,547
Investment Property [Member] \| Commercial Real Estate Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	11,446	11,482
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	58	61
Total Loans Collectively Evaluated for Impairment	575,767	557,367
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	8,469	7,529
Total Loans	587,213	568,849
Total Ending ALLL	$ 8,527	$ 7,590	6,135	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	$ 150	$ 151
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	2	2
Total Loans	150	151
Total Ending ALLL	$ 2	$ 2	$ 23	$ 31

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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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