OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Other Comprehensive Income (Loss) [Abstract]
Change in unrealized loss on securities transferred to held to maturity, after tax	$ 6	$ 7	$ 31	$ 29
Tax expense (benefit)	7,092	7,788	23,004	22,496
Net income	10,081	11,765	33,388	32,259
Change in net unrealized gain during the period, tax	(79)	(24)	(64)	2
Change in net unrealized gain during the period, after tax	(97)	(30)	(77)	3
Total defined benefit plans, tax	216	117	158	351
Change in pension and other postretirement obligations, net of deferred tax expense of $216 and $117 during the three months ended September 30, 2015 and 2014, respectively and $158 and $351 during the nine months ended September 30, 2015 and 2014, respectively	262	144	190	432
Total other comprehensive income, before tax	322	227	(1,138)	862
Total other comprehensive income, tax	146	102	(512)	387
Net other comprehensive income during during the period	176	125	(626)	475
Securities Held-To-Maturity and Transferred Securities [Member]
Other Comprehensive Income (Loss) [Abstract]
Change in non-credit component of OTTI, pre-tax	9	8	(18)	24
Change in non-credit component of OTTI, tax	4	4	(8)	13
Change in non-credit component of OTTI, after tax	5	4	(10)	11
Change in unrealized loss on securities transferred to held to maturity, pre-tax	11	12	57	50
Change in unrealized loss on securities transferred to held to maturity, tax	5	5	26	21
Change in unrealized loss on securities transferred to held to maturity, after tax	6	7	31	29
Total Securities held to maturity and transferred securities before tax	20	20	39	74
Total securities held to maturity and transferred tax	9	9	18	34
Total securities held to maturity and transferred securities, after tax	11	11	21	40
Securities Available-For-Sale [Member]
Other Comprehensive Income (Loss) [Abstract]
Change in net unrealized gain during the period, pre-tax	(176)	(54)	(141)	5
Change in net unrealized gain during the period, tax	(79)	(24)	(64)	2
Change in net unrealized gain during the period, after tax	(97)	(30)	(77)	3
Total securities available-for-sale, pre-tax	(176)	(54)	(1,525)	5
Total securities available-for-sale, tax	(79)	(24)	(688)	2
Total securities available-for-sale, after tax	(97)	(30)	(837)	3
Securities Available-For-Sale [Member] | Reclassification Out Of Accumulated Other Comprehensive Income [Member]
Other Comprehensive Income (Loss) [Abstract]
Reclassification adjustment for net gains included in net gain on securities	0	0	(1,384)	0
Tax expense (benefit)	0	0	(624)	0
Net income	0	0	(760)	0
Defined Benefit Plans [Member]
Other Comprehensive Income (Loss) [Abstract]
Change in the net actuarial gain or loss, pre-tax	0		(1,064)
Change in the net actuarial gain or loss, tax	0		(478)
Change in the net actuarial gain or loss, after tax	0		(586)
Total defined benefit plans, pre-tax	478	261	348	783
Total defined benefit plans, tax	216	117	158	351
Change in pension and other postretirement obligations, net of deferred tax expense of $216 and $117 during the three months ended September 30, 2015 and 2014, respectively and $158 and $351 during the nine months ended September 30, 2015 and 2014, respectively	262	144	190	432
Defined Benefit Plans [Member] | Reclassification Out Of Accumulated Other Comprehensive Income [Member]
Other Comprehensive Income (Loss) [Abstract]
Reclassification adjustment for expense included in salaries and employee benefits expense	478	261	1,412	783
Tax expense (benefit)	216	117	636	351
Net income	$ 262	$ 144	$ 776	$ 432