ACCUMULATED OTHER COMPREHENSIVE INCOME - Summary of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (1,058)	$ 3,353	$ 6,098
Reclassification for gains included in net income, net of tax	(24)	(61)	(89)
Current year changes, net of tax	(198)	(4,350)	(2,656)
Ending balance	(1,280)	(1,058)	3,353
Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	176	152	508
Reclassification for gains included in net income, net of tax	0	0	0
Current year changes, net of tax	116	24	(356)
Ending balance	292	176	152
Unrealized Gain (Loss) on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(1,234)	3,201	5,590
Reclassification for gains included in net income, net of tax	(24)	(61)	(89)
Current year changes, net of tax	(314)	(4,374)	(2,300)
Ending balance	$ (1,572)	$ (1,234)	$ 3,201