INVESTMENT SECURITIES - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) security	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Investments, Debt and Equity Securities [Abstract]
Number of individual securities that were in a continuous unrealized loss position for less than twelve months | security	37
Number of individual securities that were in a continuous unrealized loss position for greater than twelve months | security	22
Gross proceeds from sales of securities	$ 25,528,000	$ 44,829,000	$ 65,672,000
Impairment charges	0	0	$ 0
Carrying value of investment securities pledged	$ 89,736,000	$ 95,199,000