GOODWILL AND OTHER INTANGIBLE ASSETS (Identifiable Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 79,090	$ 79,090
Accumulated Amortization	59,233	55,270
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	27,801	27,801
Accumulated Amortization	23,269	22,782
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	49,639	49,639
Accumulated Amortization	34,922	31,821
Non-Solicitation Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,650	1,650
Accumulated Amortization	1,042	667
Trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 688	$ 688