FAIR VALUE - Carrying Amounts and Estimated Fair Values of Financial Instruments - (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financial assets
Interest bearing time deposits	$ 2,065	$ 1,960
FHLB and other stock, at cost	27,796	21,693
Interest receivable	9,095	7,342
Carrying Value
Financial assets
Cash and cash equivalents	97,505	86,552
Interest bearing time deposits	2,065	1,960
Loans including loans held for sale, net	3,045,705	2,639,046
FHLB and other stock, at cost	27,796	21,693
Interest receivable	14,849	12,576
Financial liabilities
Deposits	(3,507,603)	(3,110,871)
Other borrowings	(185,652)	(209,672)
FHLB advances	(335,986)	(249,658)
Interest payable	(1,371)	(642)
Subordinated debentures	(56,545)	(41,239)
Estimated Fair Value
Financial assets
Cash and cash equivalents	97,505	86,552
Interest bearing time deposits	2,065	1,960
Loans including loans held for sale, net	3,072,470	2,675,029
Interest receivable	14,849	12,576
Financial liabilities
Deposits	(3,503,681)	(3,107,983)
Other borrowings	(185,652)	(209,686)
FHLB advances	(331,831)	(248,944)
Interest payable	(1,371)	(642)
Subordinated debentures	(50,911)	(34,084)
Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets
Cash and cash equivalents	89,623	75,778
Financial liabilities
Deposits	(868,384)	(767,159)
Significant Other Observable Inputs (Level 2)
Financial assets
Cash and cash equivalents	7,882	10,774
Interest bearing time deposits	2,065	1,960
Loans including loans held for sale, net	7,981	12,598
Interest receivable	5,754	5,234
Financial liabilities
Deposits	(2,635,297)	(2,340,824)
Other borrowings	(185,652)	(209,686)
FHLB advances	(331,831)	(248,944)
Interest payable	(1,371)	(642)
Subordinated debentures	(50,911)	(34,084)
Significant Unobservable Inputs (Level 3)
Financial assets
Loans including loans held for sale, net	3,064,489	2,662,431
Interest receivable	$ 9,095	$ 7,342