GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Finite-Lived Intangible Assets) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Finite-lived Intangible Assets [Roll Forward]
Goodwill, beginning of period	$ 0	$ 0
Goodwill and other intangibles, net, beginning of period	2,831	2,449
Goodwill, acquired during period	21,148	0
Acquired Intangible Assets (Including Goodwill)	25,043	2,372
Amortization	(1,269)	(1,990)
Goodwill, end of period	21,148	0
Goodwill and other intangibles, net, end of period	26,605	2,831
Core Deposit Intangibles [Member]
Finite-lived Intangible Assets [Roll Forward]
CDI Balance, beginning of period	2,831	2,449
Additions through acquisitions	3,895	2,372
Amortization	(1,269)	(1,990)
CDI Balance, end of period	$ 5,457	$ 2,831
Minimum [Member] | Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	3 years
Maximum [Member] | Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		8 years