OTHER COMPREHENSIVE INCOME (LOSS), Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			$ 565,868	$ 493,947
Other comprehensive income before reclassifications			(177)	(470)
Amounts reclassified from accumulated other comprehensive loss			469	468
Other comprehensive income (loss), net of tax	$ (133)	$ (254)	292	(2)
Balance	580,448	549,611	580,448	549,611
Accumulated Other Comprehensive Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(5,939)	(8,801)
Balance	(5,647)	(8,803)	(5,647)	(8,803)
Securities Held-to-Maturity and Transferred Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(713)	(760)
Other comprehensive income before reclassifications			36	22
Amounts reclassified from accumulated other comprehensive loss			0	0
Other comprehensive income (loss), net of tax			36	22
Balance	(677)	(738)	(677)	(738)
Securities Available-for-Sale [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(92)	(122)
Other comprehensive income before reclassifications			125	34
Amounts reclassified from accumulated other comprehensive loss			0	0
Other comprehensive income (loss), net of tax			125	34
Balance	33	(88)	33	(88)
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(6,910)	(7,919)
Other comprehensive income before reclassifications			(7)	0
Amounts reclassified from accumulated other comprehensive loss			372	468
Other comprehensive income (loss), net of tax			365	468
Balance	(6,545)	(7,451)	(6,545)	(7,451)
Derivative Asset [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			1,776	0
Other comprehensive income before reclassifications			(331)	(526)
Amounts reclassified from accumulated other comprehensive loss			97	0
Other comprehensive income (loss), net of tax			(234)	(526)
Balance	$ 1,542	$ (526)	$ 1,542	$ (526)