FAIR VALUE - CARRYING AMOUNTS AND FV OF FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Assets:
Available-for-sale debt securities	$ 417,983	$ 524,303
Securities to be held to maturity	63,515	65,133
Equity securities with readily determinable fair value	2,746	2,928
Aggregate fair value of mortgage loan	4,496	5,761	$ 5,193	$ 11,662
Aggregate fair value of consumer loan	2,419	2,677	3,679	2,198
Consumer loans held for sale, at the lower of cost or fair value	7,380	8,551	$ 1,420	$ 1,310
Fair Value, Inputs, Level 1
Assets:
Cash and cash equivalents	362,122	299,351
Equity securities with readily determinable fair value	2,418	2,455
Fair Value, Inputs, Level 2
Assets:
Available-for-sale debt securities	409,963	516,727
Securities to be held to maturity	63,515	65,133
Equity securities with readily determinable fair value	328	473
Aggregate fair value of mortgage loan	4,496	5,761
Consumer loans held for sale, at the lower of cost or fair value	7,380	8,551
Accrued interest receivable	11,772	12,082
Liabilities:
Securities sold under agreements to repurchase and other short-term borrowings	175,682	204,021
Federal Home Loan Bank advances	432,140	730,712
Subordinated note	32,352	31,763
Accrued interest payable	1,041	1,100
Fair Value, Inputs, Level 2 | Non Interest Bearing Deposits
Liabilities:
Deposit liabilities, fair value	1,241,127	1,022,042
Fair Value, Inputs, Level 2 | Transaction deposits
Liabilities:
Deposit liabilities, fair value	2,098,796	2,049,493
Fair Value, Inputs, Level 2 | Time deposits.
Liabilities:
Deposit liabilities, fair value	373,075	358,627
Fair Value, Inputs, Level 3
Assets:
Available-for-sale debt securities	8,020	8,049
Aggregate fair value of consumer loan	2,419	2,677
Loans, net	3,978,974	3,938,998
Carrying Value
Assets:
Cash and cash equivalents	362,122	299,351
Available-for-sale debt securities	417,983	524,303
Securities to be held to maturity	62,844	64,227
Equity securities with readily determinable fair value	2,746	2,928
Aggregate fair value of mortgage loan	4,496	5,761
Aggregate fair value of consumer loan	2,419	2,677
Consumer loans held for sale, at the lower of cost or fair value	7,380	8,551
Loans, net	4,000,159	3,971,265
Federal Home Loan Bank stock	32,067	32,067
Accrued interest receivable	11,772	12,082
Liabilities:
Securities sold under agreements to repurchase and other short-term borrowings	175,682	204,021
Federal Home Loan Bank advances	440,000	737,500
Subordinated note	41,240	41,240
Accrued interest payable	1,041	1,100
Carrying Value | Non Interest Bearing Deposits
Liabilities:
Deposit liabilities, fair value	1,241,127	1,022,042
Carrying Value | Transaction deposits
Liabilities:
Deposit liabilities, fair value	2,098,796	2,049,493
Carrying Value | Time deposits.
Liabilities:
Deposit liabilities, fair value	377,700	361,623
Total Fair Value
Assets:
Cash and cash equivalents	362,122	299,351
Available-for-sale debt securities	417,983	524,303
Securities to be held to maturity	63,515	65,133
Equity securities with readily determinable fair value	2,746	2,928
Aggregate fair value of mortgage loan	4,496	5,761
Aggregate fair value of consumer loan	2,419	2,677
Consumer loans held for sale, at the lower of cost or fair value	7,380	8,551
Loans, net	3,978,974	3,938,998
Accrued interest receivable	11,772	12,082
Liabilities:
Securities sold under agreements to repurchase and other short-term borrowings	175,682	204,021
Federal Home Loan Bank advances	432,140	730,712
Subordinated note	32,352	31,763
Accrued interest payable	1,041	1,100
Total Fair Value | Non Interest Bearing Deposits
Liabilities:
Deposit liabilities, fair value	1,241,127	1,022,042
Total Fair Value | Transaction deposits
Liabilities:
Deposit liabilities, fair value	2,098,796	2,049,493
Total Fair Value | Time deposits.
Liabilities:
Deposit liabilities, fair value	$ 373,075	$ 358,627