GOODWILL AND CORE DEPOSIT INTANGIBLES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Goodwill
Beginning of period	$ 85,291	$ 85,291
End of the period	85,291	85,291	$ 85,291
Core Deposit Intangibles
Beginning of period	9,975	11,562
Less - amortization	(1,472)	(1,587)	(847)
End of period	8,503	9,975	11,562
Expected future amortization expense
Total expected amortization expense	9,975	$ 11,562	$ 11,562	$ 8,503
Core Deposit Intangibles
Core Deposit Intangibles
End of period	8,503
Expected future amortization expense
2018				1,196
2019				1,080
2020				992
2021				905
2022				818
Thereafter				3,512
Total expected amortization expense	$ 8,503			$ 8,503
Core Deposit Intangibles | Minimum
Core Deposit Intangibles
Useful life	6 years
Core Deposit Intangibles | Maximum
Core Deposit Intangibles
Useful life	19 years