FAIR VALUE DISCLOSURES, Fair value hierarchy (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2010
Assets [Abstract]
Residential mortgage-backed securities	$ 390,216,000		$ 390,216,000
Total Securities	478,440,000		478,440,000
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loan gross carrying value	2,214,862,000		2,214,862,000		2,234,037,000
Valuation allowance	51,817,000	51,260,000	51,817,000	51,260,000	53,400,000	52,757,000	48,495,000	45,007,000
Net recovery in provision for loan losses	411,000	514,000	702,000	702,000	1,422,000
Mortgage servicing rights fair value	1,800,000		1,800,000
Mortgage servicing rights outstanding balance	1,900,000		1,900,000
Valuation allowance for servicing rights			86,000
Mortgage servicing right recovery			22,000	7,000
Reduction in other real estate			61,000	20,000
Impaired Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loan gross carrying value	47,600,000	42,500,000	47,600,000	42,500,000
Valuation allowance	14,700,000	14,800,000	14,700,000	14,800,000
Net recovery in provision for loan losses	1,800,000	2,500,000	3,500,000	3,400,000
Commercial and Industrial Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Valuation allowance	19,696,000	22,999,000	19,696,000	22,999,000	22,830,000	22,134,000	22,549,000	21,479,000
Net recovery in provision for loan losses	286,000	133,000	472,000	230,000	826,000
Commercial Real Estate and Multi-family Residential Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Valuation allowance	24,083,000	20,032,000	24,083,000	20,032,000	23,489,000	23,236,000	17,884,000	15,893,000
Net recovery in provision for loan losses	18,000	318,000	47,000	327,000	362,000
Agri-business and Agricultural Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Valuation allowance	1,419,000	948,000	1,419,000	948,000	695,000	538,000	1,194,000	1,318,000
Net recovery in provision for loan losses	0	0	0	0	0
Consumer 1-4 Family Mortgage Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Valuation allowance	2,412,000	2,658,000	2,412,000	2,658,000	2,322,000	2,527,000	2,480,000	1,694,000
Net recovery in provision for loan losses	73,000	16,000	121,000	19,000	46,000
Level 1 [Member] | Recurring [Member]
Assets [Abstract]
U.S. Treasury securities	1,046,000		1,046,000		1,055,000
US Government Sponsored agencies	0		0		0
Residential mortgage-backed securities	0		0		0
Non-agency residential mortgage-backed securities	0		0		0
State and municipal securities	0		0		0
Total Securities	1,046,000		1,046,000		1,055,000
Mortgage banking derivative	0		0		0
Total assets	1,046,000		1,046,000		1,055,000
Liabilities [Abstract]
Mortgage banking derivative	0		0		0
Assets measured at fair value on nonrecurring basis [Abstract]
Total assets	1,046,000		1,046,000		1,055,000
Level 1 [Member] | Non-recurring [Member]
Assets [Abstract]
Total assets	0		0		0
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Mortgage servicing rights	0		0		0
Other real estate owned	0		0		0
Total assets	0		0		0
Level 1 [Member] | Non-recurring [Member] | Commercial and Industrial Loans [Member] | Working Capital Lines of Credit Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Commercial and Industrial Loans [Member] | Non working Capital Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Construction and Land Development Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Owner Occupied Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Nonowner Occupied Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Multifamily Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Agri-business and Agricultural Loans [Member] | Loans Secured by Farmland [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Agri-business and Agricultural Loans [Member] | Loans for Agricultural Production [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Other Commerical Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Closed End First Mortgage Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Open End and Junior Lien Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Residential Construction Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 1 [Member] | Non-recurring [Member] | Other Consumer Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Recurring [Member]
Assets [Abstract]
U.S. Treasury securities	0		0		0
US Government Sponsored agencies	5,298,000		5,298,000		5,277,000
Residential mortgage-backed securities	362,009,000		362,009,000		350,102,000
Non-agency residential mortgage-backed securities	28,207,000		28,207,000		32,207,000
State and municipal securities	81,239,000		81,239,000		78,064,000
Total Securities	476,753,000		476,753,000		465,650,000
Mortgage banking derivative	535,000		535,000		406,000
Total assets	477,288,000		477,288,000		466,056,000
Liabilities [Abstract]
Mortgage banking derivative	(42,000)		(42,000)		(81,000)
Assets measured at fair value on nonrecurring basis [Abstract]
Total assets	477,288,000		477,288,000		466,056,000
Level 2 [Member] | Non-recurring [Member]
Assets [Abstract]
Total assets	0		0		0
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Mortgage servicing rights	0		0		0
Other real estate owned	0		0		0
Total assets	0		0		0
Level 2 [Member] | Non-recurring [Member] | Commercial and Industrial Loans [Member] | Working Capital Lines of Credit Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Commercial and Industrial Loans [Member] | Non working Capital Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Construction and Land Development Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Owner Occupied Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Nonowner Occupied Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Multifamily Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Agri-business and Agricultural Loans [Member] | Loans Secured by Farmland [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Agri-business and Agricultural Loans [Member] | Loans for Agricultural Production [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Other Commerical Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Closed End First Mortgage Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Open End and Junior Lien Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Residential Construction Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 2 [Member] | Non-recurring [Member] | Other Consumer Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 3 [Member] | Recurring [Member]
Assets [Abstract]
U.S. Treasury securities	0		0		0
US Government Sponsored agencies	0		0		0
Residential mortgage-backed securities	0		0		0
Non-agency residential mortgage-backed securities	0		0		0
State and municipal securities	641,000		641,000		686,000
Total Securities	641,000		641,000		686,000
Mortgage banking derivative	0		0		0
Total assets	641,000		641,000		686,000
Liabilities [Abstract]
Mortgage banking derivative	0		0		0
Assets measured at fair value on nonrecurring basis [Abstract]
Total assets	641,000		641,000		686,000
Level 3 [Member] | Non-recurring [Member]
Assets [Abstract]
Total assets	35,474,000		35,474,000		46,444,000
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	32,831,000		32,831,000		43,980,000
Mortgage servicing rights	1,838,000		1,838,000		1,734,000
Other real estate owned	805,000		805,000		730,000
Total assets	35,474,000		35,474,000		46,444,000
Level 3 [Member] | Non-recurring [Member] | Commercial and Industrial Loans [Member] | Working Capital Lines of Credit Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	1,539,000		1,539,000		2,762,000
Level 3 [Member] | Non-recurring [Member] | Commercial and Industrial Loans [Member] | Non working Capital Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	5,102,000		5,102,000		11,885,000
Level 3 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Construction and Land Development Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	1,486,000		1,486,000		303,000
Level 3 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Owner Occupied Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	3,136,000		3,136,000		3,515,000
Level 3 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Nonowner Occupied Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	20,646,000		20,646,000		23,591,000
Level 3 [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Multifamily Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 3 [Member] | Non-recurring [Member] | Agri-business and Agricultural Loans [Member] | Loans Secured by Farmland [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	266,000		266,000		433,000
Level 3 [Member] | Non-recurring [Member] | Agri-business and Agricultural Loans [Member] | Loans for Agricultural Production [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		207,000
Level 3 [Member] | Non-recurring [Member] | Other Commerical Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 3 [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Closed End First Mortgage Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	514,000		514,000		878,000
Level 3 [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Open End and Junior Lien Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	141,000		141,000		406,000
Level 3 [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Residential Construction Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Level 3 [Member] | Non-recurring [Member] | Other Consumer Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	1,000		1,000		0
Fair Value [Member] | Recurring [Member]
Assets [Abstract]
U.S. Treasury securities	1,046,000		1,046,000		1,055,000
US Government Sponsored agencies	5,298,000		5,298,000		5,277,000
Residential mortgage-backed securities	362,009,000		362,009,000		350,102,000
Non-agency residential mortgage-backed securities	28,207,000		28,207,000		32,207,000
State and municipal securities	81,880,000		81,880,000		78,750,000
Total Securities	478,440,000		478,440,000		467,391,000
Mortgage banking derivative	535,000		535,000		406,000
Total assets	478,975,000		478,975,000		467,797,000
Liabilities [Abstract]
Mortgage banking derivative	(42,000)		(42,000)		(81,000)
Assets measured at fair value on nonrecurring basis [Abstract]
Total assets	478,975,000		478,975,000		467,797,000
Fair Value [Member] | Non-recurring [Member]
Assets [Abstract]
Total assets	35,474,000		35,474,000		46,444,000
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	32,831,000		32,831,000		43,980,000
Mortgage servicing rights	1,838,000		1,838,000		1,734,000
Other real estate owned	805,000		805,000		730,000
Total assets	35,474,000		35,474,000		46,444,000
Fair Value [Member] | Non-recurring [Member] | Commercial and Industrial Loans [Member] | Working Capital Lines of Credit Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	1,539,000		1,539,000		2,762,000
Fair Value [Member] | Non-recurring [Member] | Commercial and Industrial Loans [Member] | Non working Capital Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	5,102,000		5,102,000		11,885,000
Fair Value [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Construction and Land Development Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	1,486,000		1,486,000		303,000
Fair Value [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Owner Occupied Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	3,136,000		3,136,000		3,515,000
Fair Value [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Nonowner Occupied Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	20,646,000		20,646,000		23,591,000
Fair Value [Member] | Non-recurring [Member] | Commercial Real Estate and Multi-family Residential Loans [Member] | Multifamily Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Fair Value [Member] | Non-recurring [Member] | Agri-business and Agricultural Loans [Member] | Loans Secured by Farmland [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	266,000		266,000		433,000
Fair Value [Member] | Non-recurring [Member] | Agri-business and Agricultural Loans [Member] | Loans for Agricultural Production [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		207,000
Fair Value [Member] | Non-recurring [Member] | Other Commerical Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Fair Value [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Closed End First Mortgage Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	514,000		514,000		878,000
Fair Value [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Open End and Junior Lien Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	141,000		141,000		406,000
Fair Value [Member] | Non-recurring [Member] | Consumer 1-4 Family Mortgage Loans [Member] | Residential Construction Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	0		0		0
Fair Value [Member] | Non-recurring [Member] | Other Consumer Loans [Member]
Assets measured at fair value on nonrecurring basis [Abstract]
Impaired loans	1,000		1,000		0
State and Municipal Securities [Member]
Assets [Abstract]
Total Securities	$ 641,000		$ 641,000