FAIR VALUE MEASUREMENTS (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Financial Assets
Trading security	$ 14,909	$ 14,840
Securities available for sale	1,091,818	760,048
Securities held to maturity	44,997	45,764
Accrued interest receivable	17,274	15,070
Assets held for sale	1,280	3,969
Financial Liabilities
Liabilities held for sale		24,834
Methods and assumptions used to estimate the fair value of significant classes of financial instruments
Junior subordinated debentures re-price period	90 days
Level 1
Financial Assets
Cash and cash equivalents	71,754	75,539
Securities available for sale	53,806	20,891
Derivative assets		242
Financial Liabilities
Derivative liabilities	417
Level 2
Financial Assets
Securities available for sale	1,035,686	737,193
Restricted equity securities	55,720	50,282
Loans held for sale	19,493	15,840
Accrued interest receivable	17,274	15,072
Cash surrender value of bank-owned life insurance policies	104,588	101,530
Derivative assets	12,328	7,799
Assets held for sale	1,280	3,969
Financial Liabilities
Total deposits	4,655,234	3,848,926
Short-term debt	900,983	872,545
Long-term Federal Home Loan Bank advances	63,283	103,660
Subordinated borrowings	93,441	87,882
Derivative liabilities	18,259	11,964
Liabilities held for sale		24,834
Level 3
Financial Assets
Trading security	14,909	14,840
Securities available for sale	2,326	1,964
Securities held to maturity	44,997	45,764
Net loans	4,695,256	4,154,663
Derivative assets	625	277
Financial Liabilities
Derivative liabilities	93
Carrying Amount
Financial Assets
Cash and cash equivalents	71,754	75,539
Trading security	14,909	14,840
Securities available for sale	1,091,818	760,048
Securities held to maturity	43,347	44,921
Restricted equity securities	55,720	50,282
Net loans	4,644,938	4,147,200
Loans held for sale	19,493	15,840
Accrued interest receivable	17,274	15,072
Cash surrender value of bank-owned life insurance policies	104,588	101,530
Derivative assets	12,953	8,318
Assets held for sale	1,280	3,969
Financial Liabilities
Total deposits	4,654,679	3,848,529
Short-term debt	900,900	872,510
Long-term Federal Home Loan Bank advances	61,676	101,918
Subordinated borrowings	89,747	89,679
Derivative liabilities	18,769	11,964
Liabilities held for sale		24,834
Total Fair Value
Financial Assets
Cash and cash equivalents	71,754	75,539
Trading security	14,909	14,840
Securities available for sale	1,091,818	760,048
Securities held to maturity	44,997	45,764
Restricted equity securities	55,720	50,282
Net loans	4,695,256	4,154,663
Loans held for sale	19,493	15,840
Accrued interest receivable	17,274	15,072
Cash surrender value of bank-owned life insurance policies	104,588	101,530
Derivative assets	12,953	8,318
Assets held for sale	1,280	3,969
Financial Liabilities
Total deposits	4,655,234	3,848,926
Short-term debt	900,983	872,545
Long-term Federal Home Loan Bank advances	63,283	103,660
Subordinated borrowings	93,441	87,882
Derivative liabilities	18,769	11,964
Liabilities held for sale		$ 24,834