ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Changes in Accumulated Other Comprehensive Income (Loss) By Component (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
AOCI Attributable to Parent, Net of Tax
Balance	$ 156,503
Accretion of unrealized losses of securities transferred from available-for-sale to held-to-maturity recognized in other comprehensive income	113	$ 127
Other comprehensive income	125	2,861
Balance	158,648
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax
Balance	(5,782)	(6,023)
Other comprehensive income before reclassifications	106	2,659
Accretion of unrealized losses of securities transferred from available-for-sale to held-to-maturity recognized in other comprehensive income	113	127
Reclassification adjustments for (gains) losses reclassified into income	94	(75)
Net current periodic change, Accumulated other comprehensive income (loss)	125	2,861
Balance	(5,657)	(3,162)
Unrealized Gains (Losses) on Securities | Available-For-Sale
AOCI Attributable to Parent, Net of Tax
Balance	(551)	166
Other comprehensive income before reclassifications	106	2,624
Reclassification adjustments for (gains) losses reclassified into income	166
Net current periodic change, Accumulated other comprehensive income (loss)	(60)	2,624
Balance	(611)	2,790
Unrealized Gains (Losses) on Securities | Transferred From Available-For-Sale to Held-To-Maturity
AOCI Attributable to Parent, Net of Tax
Balance	(1,408)	(2,297)
Accretion of unrealized losses of securities transferred from available-for-sale to held-to-maturity recognized in other comprehensive income	113	127
Net current periodic change, Accumulated other comprehensive income (loss)	113	127
Balance	(1,295)	(2,170)
Pension Plan.
AOCI Attributable to Parent, Net of Tax
Balance	(3,823)	(3,737)
Reclassification adjustments for (gains) losses reclassified into income	(72)	(75)
Net current periodic change, Accumulated other comprehensive income (loss)	72	75
Balance	$ (3,751)	(3,662)
Interest Rate Swaps
AOCI Attributable to Parent, Net of Tax
Balance		(155)
Other comprehensive income before reclassifications		35
Net current periodic change, Accumulated other comprehensive income (loss)		35
Balance		$ (120)