GOODWILL AND OTHER INTANGIBLE ASSETS (Identifiable Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 79,090	$ 76,218
Accumulated Amortization	55,270	50,827
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	27,801	27,801
Accumulated Amortization	22,782	22,256
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	49,639	46,967
Accumulated Amortization	31,821	28,329
Non-Solicitation Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,650	1,450
Accumulated Amortization	667	242
Trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 688	$ 688