FAIR VALUE OF FINANCIAL INSTRUMENTS- Carrying values and fair value (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets
Investment securities available for sale	$ 385,340	$ 246,339
Investment securities held to maturity	79,612	81,952
Accrued interest receivable	10,322	8,202
Liabilities
Trust preferred debentures	45,156	37,405
Accrued interest payable	1,555	1,045
Level 1
Assets
Cash and due from banks	332,422	189,543
Federal funds sold	1,934	1,173
Investment securities available for sale	25,936	75,901
Level 2
Assets
Investment securities available for sale	354,664	162,957
Investment securities held to maturity	79,612	81,952
Nonmarketable equity securities	28,891	19,485
Loans held for sale	41,689	70,565
Accrued interest receivable	10,322	8,202
Liabilities
Deposits	3,330,855	2,404,231
Short-term borrowings	170,629	131,557
FHLB and other borrowings	399,365	236,736
Subordinated debt	49,966	49,692
Trust preferred debentures	43,108	33,054
Accrued interest payable	1,555	1,045
Level 3
Assets
Investment securities available for sale	4,740	7,481
Loans, net	3,170,384	2,305,206
Carrying value
Assets
Cash and due from banks	332,422	189,543
Federal funds sold	1,934	1,173
Investment securities available for sale	385,340	246,339
Investment securities held to maturity	75,371	78,672
Nonmarketable equity securities	28,891	19,485
Loans, net	3,168,639	2,305,114
Loans held for sale	41,689	70,565
Accrued interest receivable	10,322	8,202
Liabilities
Deposits	3,333,031	2,404,366
Short-term borrowings	170,629	131,557
FHLB and other borrowings	400,304	237,518
Subordinated debt	54,556	54,508
Trust preferred debentures	45,156	37,405
Accrued interest payable	1,555	1,045
Fair value
Assets
Cash and due from banks	332,422	189,543
Federal funds sold	1,934	1,173
Investment securities available for sale	385,340	246,339
Investment securities held to maturity	79,612	81,952
Nonmarketable equity securities	28,891	19,485
Loans, net	3,170,384	2,305,206
Loans held for sale	41,689	70,565
Accrued interest receivable	10,322	8,202
Liabilities
Deposits	3,330,855	2,404,231
Short-term borrowings	170,629	131,557
FHLB and other borrowings	399,365	236,736
Subordinated debt	49,966	49,692
Trust preferred debentures	43,108	33,054
Accrued interest payable	1,555	1,045
Interest rate lock commitments | Level 2
Assets
Derivative Assets	7,396	6,253
Interest rate lock commitments | Carrying value
Assets
Derivative Assets	7,396	6,253
Interest rate lock commitments | Fair value
Assets
Derivative Assets	7,396	6,253
Forward commitments to sell mortgage-backed securities | Level 2
Assets
Derivative Assets	91	125
Forward commitments to sell mortgage-backed securities | Carrying value
Assets
Derivative Assets	91	125
Forward commitments to sell mortgage-backed securities | Fair value
Assets
Derivative Assets	91	$ 125
Interest rate swap contracts | Level 2
Assets
Derivative Assets	126
Liabilities
Derivative Liability	126
Interest rate swap contracts | Carrying value
Assets
Derivative Assets	126
Liabilities
Derivative Liability	126
Interest rate swap contracts | Fair value
Assets
Derivative Assets	126
Liabilities
Derivative Liability	$ 126