GOODWILL AND OTHER INTANGIBLE ASSETS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012		Jun. 30, 2011	Dec. 31, 2011
Carrying amounts of goodwill [Roll Forward]
Balance, beginning of period			$ 271,297	[1]
Goodwill recorded during the period			0
Balance, end of period	271,297	271,297	271,297		271,297
Amortized intangible assets [Abstract]
Gross Carrying Amount	60,625		60,625			60,625
Accumulated Amortization	46,205		46,205			44,701
Aggregate amortization expense [Abstract]
Total	762	832	1,504		1,687
Estimated Amortization Expense:
For year ending December 31, 2012			2,940
For year ending December 31, 2013			2,250
For year ending December 31, 2014			1,944
For year ending December 31, 2015			1,615
For year ending December 31, 2016			1,274
Trade names [Member]
Unamortized intangible assets [Abstract]
Gross Carrying Amount	688		688			688
Core deposit intangibles [Member]
Amortized intangible assets [Abstract]
Gross Carrying Amount	27,801		27,801			27,801
Accumulated Amortization	21,204		21,204			20,728
Aggregate amortization expense [Abstract]
Total	242	248	476		515
Estimated Amortization Expense:
For year ending December 31, 2012			946
For year ending December 31, 2013			582
For year ending December 31, 2014			526
For year ending December 31, 2015			487
For year ending December 31, 2016			451
Customer relationship intangibles [Member]
Amortized intangible assets [Abstract]
Gross Carrying Amount	32,749		32,749			32,749
Accumulated Amortization	24,944		24,944			23,935
Aggregate amortization expense [Abstract]
Total	511	575	1,009		1,153
Estimated Amortization Expense:
For year ending December 31, 2012			1,957
For year ending December 31, 2013			1,668
For year ending December 31, 2014			1,418
For year ending December 31, 2015			1,128
For year ending December 31, 2016			823
Non-solicitation intangibles [Member]
Amortized intangible assets [Abstract]
Gross Carrying Amount	75		75			75
Accumulated Amortization	57		57			38
Aggregate amortization expense [Abstract]
Total	9	9	19		19
Estimated Amortization Expense:
For year ending December 31, 2012			37
For year ending December 31, 2013			0
For year ending December 31, 2014			0
For year ending December 31, 2015			0
For year ending December 31, 2016			0
Community Banking [Member]
Carrying amounts of goodwill [Roll Forward]
Balance, beginning of period			217,618
Goodwill recorded during the period			0
Balance, end of period	217,618		217,618
Insurance Agencies [Member]
Carrying amounts of goodwill [Roll Forward]
Balance, beginning of period			53,679
Goodwill recorded during the period			0
Balance, end of period	$ 53,679		$ 53,679

[1] Derived from audited financial statements.