LOANS (Schedule of Balances by Portfolio Class, Based on Impairment Method) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Total Loans Individually Evaluated for Impairment	$ 26,643		$ 23,107
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	580		490
Total Loans Collectively Evaluated for Impairment	3,120,661		2,888,445
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	28,639		25,366
Total Loans	3,147,304		2,911,552
Total Ending ALLL	29,219	$ 27,321	25,856	$ 22,969	$ 20,816	$ 19,480
Residential Portfolio Segment [Member] | Junior Lien [Member]
Total Loans Individually Evaluated for Impairment	166		176
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	10,310		11,327
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	19		66
Total Loans	10,476		11,503
Total Ending ALLL	19	13	66	73	71	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	72,844		47,635
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	247		112
Total Loans	72,844		47,635
Total Ending ALLL	247	136	112	93	77	96
Primary Residential Mortgages [Member] | Residential Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	13,374		9,752
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	228		291
Total Loans Collectively Evaluated for Impairment	496,688		473,333
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	2,555		2,006
Total Loans	510,062		483,085
Total Ending ALLL	2,783	2,503	2,297	2,409	2,314	2,923
Home Equity Lines of Credit [Member] | Residential Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	150		254
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	63,038		52,550
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	223		86
Total Loans	63,188		52,804
Total Ending ALLL	223	133	86	113	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	1,501,915		1,416,775
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	11,639		11,813
Total Loans	1,501,915		1,416,775
Total Ending ALLL	11,639	11,631	11,813	8,623	8,738	8,983
Owner Occupied Property [Member] | Commercial Real Estate Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	1,241		1,272
Ending ALLL Attributable to Loans Individually Evaluated for Impairment
Total Loans Collectively Evaluated for Impairment	164,883		175,004
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	1,733		1,679
Total Loans	166,124		176,276
Total Ending ALLL	1,733	1,683	1,679	2,286	2,347	1,547
Investment Property [Member] | Commercial Real Estate Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	11,488		11,482
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	219		61
Total Loans Collectively Evaluated for Impairment	631,042		557,367
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	9,402		7,529
Total Loans	642,530		568,849
Total Ending ALLL	9,621	8,527	7,590	7,779	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	99		151
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	1		2
Total Loans	99		151
Total Ending ALLL	1	2	2	2	23	31
Commercial and Industrial Sector [Member] | Commercial Portfolio Segment [Member]
Total Loans Individually Evaluated for Impairment	224		171
Ending ALLL Attributable to Loans Individually Evaluated for Impairment	133		138
Total Loans Collectively Evaluated for Impairment	179,668		154,124
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	2,818		2,071
Total Loans	179,892		154,295
Total Ending ALLL	2,951	2,691	2,209	1,589	1,011	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	174		179
Ending ALLL Attributable to Loans Collectively Evaluated for Impairment	2		2
Total Loans	174		179
Total Ending ALLL	$ 2	$ 2	$ 2	$ 2	$ 3	$ 4