DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financial Assets:
Available-for-sale securities	$ 664,045	$ 705,539
Level 1
Financial Assets:
Available-for-sale securities	0	0
Loans held for sale	0	0
Level 2
Financial Assets:
Available-for-sale securities	664,045	705,539
Loans held for sale	7,461	7,156
Level 3
Financial Assets:
Available-for-sale securities	0	0
Loans held for sale	0	0
Recurring
Financial Assets:
Available-for-sale securities	664,045	705,539
Loans held for sale	7,461
Financial Liabilities:
Derivative liability		1,325
Recurring | Interest rate swaps
Financial Assets:
Derivative asset		1,326
Recurring | Interest rate caps and collars
Financial Assets:
Derivative asset		423
Financial Liabilities:
Derivative liability		448
Recurring | Level 1
Financial Assets:
Available-for-sale securities	0	0
Loans held for sale	0
Recurring | Level 1 | Interest rate swaps
Financial Assets:
Derivative asset		0
Recurring | Level 1 | Interest rate caps and collars
Financial Assets:
Derivative asset		0
Financial Liabilities:
Derivative liability		0
Recurring | Level 2
Financial Assets:
Available-for-sale securities	664,045	705,539
Loans held for sale	7,461
Recurring | Level 2 | Interest rate swaps
Financial Assets:
Derivative asset		1,326
Recurring | Level 2 | Interest rate caps and collars
Financial Assets:
Derivative asset		423
Financial Liabilities:
Derivative liability		448
Recurring | Level 3
Financial Assets:
Available-for-sale securities	0	0
Loans held for sale	0
Recurring | Level 3 | Interest rate swaps
Financial Assets:
Derivative asset		0
Recurring | Level 3 | Interest rate caps and collars
Financial Assets:
Derivative asset		0
Financial Liabilities:
Derivative liability		0
Correspondent | Recurring | Interest rate swaps
Financial Assets:
Derivative asset	2,309
Financial Liabilities:
Derivative liability	493
Correspondent | Recurring | Interest rate caps and collars
Financial Assets:
Derivative asset	150	75
Correspondent | Recurring | Level 1 | Interest rate swaps
Financial Assets:
Derivative asset	0
Financial Liabilities:
Derivative liability	0
Correspondent | Recurring | Level 1 | Interest rate caps and collars
Financial Assets:
Derivative asset	0	0
Correspondent | Recurring | Level 2 | Interest rate swaps
Financial Assets:
Derivative asset	2,309
Financial Liabilities:
Derivative liability	493
Correspondent | Recurring | Level 2 | Interest rate caps and collars
Financial Assets:
Derivative asset	150	75
Correspondent | Recurring | Level 3 | Interest rate swaps
Financial Assets:
Derivative asset	0
Financial Liabilities:
Derivative liability	0
Correspondent | Recurring | Level 3 | Interest rate caps and collars
Financial Assets:
Derivative asset	0	0
Customer | Recurring | Interest rate swaps
Financial Assets:
Derivative asset	417
Financial Liabilities:
Derivative liability	2,298
Customer | Recurring | Interest rate caps and collars
Financial Liabilities:
Derivative liability	150	75
Customer | Recurring | Level 1 | Interest rate swaps
Financial Assets:
Derivative asset	0
Financial Liabilities:
Derivative liability	0	0
Customer | Recurring | Level 1 | Interest rate caps and collars
Financial Liabilities:
Derivative liability	0	0
Customer | Recurring | Level 2 | Interest rate swaps
Financial Assets:
Derivative asset	417
Financial Liabilities:
Derivative liability	2,298	1,325
Customer | Recurring | Level 2 | Interest rate caps and collars
Financial Liabilities:
Derivative liability	150	75
Customer | Recurring | Level 3 | Interest rate swaps
Financial Assets:
Derivative asset	0
Financial Liabilities:
Derivative liability	0	0
Customer | Recurring | Level 3 | Interest rate caps and collars
Financial Liabilities:
Derivative liability	$ 0	$ 0