DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financial Assets:
Available-for-sale securities	$ 635,333	$ 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	635,333	705,539
Loans held for sale	4,992	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	635,333	705,539
Loans held for sale	4,992
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	635,333	705,539
Loans held for sale	4,992
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	2,757
Financial Liabilities:
Derivative liability	242
Correspondent | Recurring | Interest rate caps and collars
Financial Assets:
Derivative asset	185	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	2,757
Financial Liabilities:
Derivative liability	242
Correspondent | Recurring | Level 2 | Interest rate caps and collars
Financial Assets:
Derivative asset	185	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	188
Financial Liabilities:
Derivative liability	2,752
Customer | Recurring | Interest rate caps and collars
Financial Liabilities:
Derivative liability	185	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	188
Financial Liabilities:
Derivative liability	2,752	1,325
Customer | Recurring | Level 2 | Interest rate caps and collars
Financial Liabilities:
Derivative liability	185	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