SHAREHOLDERS’ EQUITY AND EARNINGS PER COMMON SHARE - Changes in AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	$ 156,740	$ 154,152	$ 146,287
Other comprehensive gain (loss) before reclassifications	(229)	(5,049)	(2,220)
Less: amounts reclassified from accumulated other comprehensive income	1	(2,906)	(842)
Total other comprehensive loss	(228)	(7,955)	(3,062)
Balance at end of period	354,641	156,740	154,152
Net unrealized loss on AFS securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(2,125)	5,713	7,901
Other comprehensive gain (loss) before reclassifications	426	(4,914)	(1,321)
Less: amounts reclassified from accumulated other comprehensive income	(12)	(2,924)	(867)
Total other comprehensive loss	414	(7,838)	(2,188)
Balance at end of period	(1,711)	(2,125)	5,713
Net unrealized loss on derivative hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(1,798)	(1,621)	(722)
Other comprehensive gain (loss) before reclassifications	(452)	(177)	(899)
Less: amounts reclassified from accumulated other comprehensive income	0	0	0
Total other comprehensive loss	(452)	(177)	(899)
Balance at end of period	(2,250)	(1,798)	(1,621)
Net unrealized loss on post-retirement plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(403)	(463)	(488)
Other comprehensive gain (loss) before reclassifications	(203)	42	0
Less: amounts reclassified from accumulated other comprehensive income	13	18	25
Total other comprehensive loss	(190)	60	25
Balance at end of period	(593)	(403)	(463)
Accumulated other comprehensive (loss) income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(4,326)	3,629	6,691
Total other comprehensive loss	(228)	(7,955)	(3,062)
Balance at end of period	$ (4,554)	$ (4,326)	$ 3,629