ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY (Aging Of The Recorded Investment In Past Due Loans) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	$ 4,037	$ 4,225
Greater than 90 Days Past Due	33,568	39,504
Total Past Due	37,605	43,729
Loans Not Past Due	2,165,783	2,189,980
Total ending loan balance	2,203,388	2,233,709
Commercial and Industrial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total ending loan balance	829,019	751,364
Commercial Real Estate and Multi-Family Residential Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total ending loan balance	784,363	851,677
Agri-business and Agricultural Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total ending loan balance	214,170	238,003
Other Commercial [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total ending loan balance	44,974	58,249
Consumer 1-4 Family Mortgage Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total ending loan balance	286,221	288,456
Other Consumer [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total ending loan balance	44,641	45,960
Unallocated [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total ending loan balance	0	0
Other Commerical Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	0	0
Greater than 90 Days Past Due	0	0
Total Past Due	0	0
Loans Not Past Due	44,974	58,249
Total ending loan balance	44,974	58,249
Other Consumer Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	235	192
Greater than 90 Days Past Due	54	7
Total Past Due	289	199
Loans Not Past Due	44,352	45,761
Total ending loan balance	44,641	45,960
Non-working Capital Loans [Member] | Commercial and Industrial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	246	21
Greater than 90 Days Past Due	5,349	5,433
Total Past Due	5,595	5,454
Loans Not Past Due	377,276	372,018
Total ending loan balance	382,871	377,472
Owner Occupied Loans [Member] | Commercial Real Estate and Multi-Family Residential Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	860	104
Greater than 90 Days Past Due	2,876	4,371
Total Past Due	3,736	4,475
Loans Not Past Due	359,747	342,068
Total ending loan balance	363,483	346,543
Closed End First Mortgage Loans [Member] | Consumer 1-4 Family Mortgage Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	2,123	2,569
Greater than 90 Days Past Due	566	1,245
Total Past Due	2,689	3,814
Loans Not Past Due	103,210	102,970
Total ending loan balance	105,899	106,784
Open End and Junior Lien Loans [Member] | Consumer 1-4 Family Mortgage Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	197	254
Greater than 90 Days Past Due	426	452
Total Past Due	623	706
Loans Not Past Due	168,424	175,517
Total ending loan balance	171,568	176,223
Working Capital Lines Of Credit Loans [Member] | Commercial and Industrial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	332	1,051
Greater than 90 Days Past Due	2,012	4,743
Total Past Due	2,344	5,794
Loans Not Past Due	443,804	368,098
Total ending loan balance	446,148	373,892
Construction and Land Development Loans [Member] | Commercial Real Estate and Multi-Family Residential Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	0	0
Greater than 90 Days Past Due	1,890	429
Total Past Due	1,890	429
Loans Not Past Due	85,856	81,650
Total ending loan balance	87,746	82,079
Nonowner Occupied Loans [Member] | Commercial Real Estate and Multi-Family Residential Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	0	0
Greater than 90 Days Past Due	19,575	21,971
Total Past Due	19,575	21,971
Loans Not Past Due	288,125	362,710
Total ending loan balance	332,753	384,681
Multifamily Loans [Member] | Commercial Real Estate and Multi-Family Residential Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	0	0
Greater than 90 Days Past Due	0	0
Total Past Due	0	0
Loans Not Past Due	25,434	38,374
Total ending loan balance	25,434	38,374
Loans Secured By Farmland [Member] | Agri-business and Agricultural Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	0	0
Greater than 90 Days Past Due	820	628
Total Past Due	820	628
Loans Not Past Due	118,717	117,619
Total ending loan balance	119,537	118,247
Loans For Agricultural Production [Member] | Agri-business and Agricultural Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	0	0
Greater than 90 Days Past Due	0	225
Total Past Due	0	225
Loans Not Past Due	94,633	119,531
Total ending loan balance	94,633	119,756
Residential Construction and Land Development Loans [Member] | Consumer 1-4 Family Mortgage Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
30 to 89 Days Past Due	44	34
Greater than 90 Days Past Due	0	9
Total Past Due	44	34
Loans Not Past Due	11,231	5,415
Total ending loan balance	$ 11,275	$ 5,449