GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 48,390	$ 41,866
Accumulated Amortization	(29,695)	(26,352)
Net Carrying Amount	18,695	15,514
Finite-lived intangible assets, future amortization expense [Abstract]
Oct - Dec 2012	1,264
2013	4,441
2014	3,597
2015	2,804
2016	2,095
Thereafter	4,494
Total	18,695
Components of goodwill [Abstract]
Goodwill	374,527	349,874
Goodwill, Acquisition	24,653
Accumulated Impairment	(4,824)	(4,824)
Accumulated impairment, Acquisition	0
Goodwill, net	369,703	345,050	344,229
Goodwill, net, Acquisition	24,653
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	38,961	32,437
Accumulated Amortization	(23,457)	(20,918)
Net Carrying Amount	15,504	11,519
Other Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	9,429	9,429
Accumulated Amortization	(6,238)	(5,434)
Net Carrying Amount	$ 3,191	$ 3,995

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Balance Type:	na
Period Type:	duration

The accumulated amount of amortization of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.