FAIR VALUE - CARRYING AMOUNTS AND FV OF FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets:
Securities available for sale	$ 517,058	$ 435,911
Securities to be held to maturity	39,196	45,807
Carrying Value
Assets:
Cash and cash equivalents	210,082	72,878
Securities available for sale	517,058	435,911
Securities to be held to maturity	38,727	45,437
Mortgage loans held for sale	4,083	6,388
Other loans held for sale	514
Loans, net	3,299,119	3,016,085
Federal Home Loan Bank stock	28,208	28,208
Accrued interest receivable	9,233	8,807
Liabilities:
Securities sold under agreements to repurchase and other short-term borrowings	395,433	356,108
Federal Home Loan Bank advances	699,500	707,500
Subordinated note	41,240	41,240
Accrued interest payable	1,229	1,262
Carrying Value | Non Interest Bearing Deposits
Liabilities:
Deposit liabilities, fair value	634,863	502,569
Carrying Value | Transaction deposits
Liabilities:
Deposit liabilities, fair value	1,601,647	1,290,400
Carrying Value | Time deposits.
Liabilities:
Deposit liabilities, fair value	250,967	265,213
Total Fair Value
Assets:
Cash and cash equivalents	210,082	72,878
Securities available for sale	517,058	435,911
Securities to be held to maturity	39,196	45,807
Mortgage loans held for sale	4,083	6,388
Other loans held for sale	514
Loans, net	3,332,608	3,045,443
Accrued interest receivable	9,233	8,807
Liabilities:
Securities sold under agreements to repurchase and other short-term borrowings	395,433	356,108
Federal Home Loan Bank advances	708,722	721,346
Subordinated note	33,358	41,198
Accrued interest payable	1,229	1,262
Total Fair Value | Non Interest Bearing Deposits
Liabilities:
Deposit liabilities, fair value	634,863	502,569
Total Fair Value | Transaction deposits
Liabilities:
Deposit liabilities, fair value	1,601,647	1,290,400
Total Fair Value | Time deposits.
Liabilities:
Deposit liabilities, fair value	250,882	265,858
Total Fair Value | Fair Value, Inputs, Level 1
Assets:
Cash and cash equivalents	210,082	72,878
Securities available for sale	1,011	1,018
Total Fair Value | Fair Value, Inputs, Level 2
Assets:
Securities available for sale	507,510	429,643
Securities to be held to maturity	39,196	45,807
Mortgage loans held for sale	4,083	6,388
Other loans held for sale	514
Accrued interest receivable	9,233	8,807
Liabilities:
Securities sold under agreements to repurchase and other short-term borrowings	395,433	356,108
Federal Home Loan Bank advances	708,722	721,346
Subordinated note	33,358	41,198
Accrued interest payable	1,229	1,262
Total Fair Value | Fair Value, Inputs, Level 2 | Non Interest Bearing Deposits
Liabilities:
Deposit liabilities, fair value	634,863	502,569
Total Fair Value | Fair Value, Inputs, Level 2 | Transaction deposits
Liabilities:
Deposit liabilities, fair value	1,601,647	1,290,400
Total Fair Value | Fair Value, Inputs, Level 2 | Time deposits.
Liabilities:
Deposit liabilities, fair value	250,882	265,858
Total Fair Value | Fair Value, Inputs, Level 3
Assets:
Securities available for sale	8,537	5,250
Loans, net	$ 3,332,608	$ 3,045,443