BENEFIT PLANS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Change in plan assets [Roll Forward]
Fair value of plan assets at end of year		$ 177,551	[1]	$ 173,081	[1]
Amounts recognized in accumulated other comprehensive income (AOCI) [Abstract]
AOCI at year end		16,716		7,145		27,785
Pension Benefits [Member]
Change in benefit obligation [Roll Forward]
Benefit obligation at the beginning of year		111,174		123,739
Service cost		3,530		3,988		3,392
Interest cost		5,271		4,120		4,393
Plan amendment		2,091		0
Participant contributions		0		0
Deferred actuarial loss (gain)		13,005		(14,610)
Benefits paid		(7,558)		(6,063)
Benefit obligation at end of year		127,513		111,174		123,739
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year		173,416		143,661
Actual return of plan assets		11,391		25,196
Participant contributions		0		0
Employer contributions	10,000	616		10,622
Benefits paid		(7,558)		(6,063)
Fair value of plan assets at end of year		177,865		173,416		143,661
Defined Benefit Plan, Funded Status of Plan [Abstract]
Over/(Under) funded status at year end		50,352		62,242
Amounts recognized in the consolidated balance sheet [Abstract]
Other assets		61,437		73,790
Other liabilities		(11,085)		(11,548)
Amounts recognized in accumulated other comprehensive income (AOCI) [Abstract]
Net loss (gain)		26,748		12,905
Net prior service cost (credit)		2,316		797
Pre-tax AOCI		29,064		13,702
Taxes		(11,033)		(5,095)
AOCI at year end		18,031		8,607
Post-retirement Benefits [Member]
Change in benefit obligation [Roll Forward]
Benefit obligation at the beginning of year		2,340		3,051
Service cost		0		0		0
Interest cost		102		88		114
Plan amendment		0		0
Participant contributions		551		608
Deferred actuarial loss (gain)		55		(301)
Benefits paid		(792)		(1,106)
Benefit obligation at end of year		2,256		2,340		3,051
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year		0		0
Actual return of plan assets		0		0
Participant contributions		551		608
Employer contributions		241		498
Benefits paid		(792)		(1,106)
Fair value of plan assets at end of year		0		0		0
Defined Benefit Plan, Funded Status of Plan [Abstract]
Over/(Under) funded status at year end		(2,256)		(2,340)
Amounts recognized in the consolidated balance sheet [Abstract]
Other assets		0		0
Other liabilities		(2,256)		(2,340)
Amounts recognized in accumulated other comprehensive income (AOCI) [Abstract]
Net loss (gain)		36		(25)
Net prior service cost (credit)		(2,159)		(2,338)
Pre-tax AOCI		(2,123)		(2,363)
Taxes		808		901
AOCI at year end		(1,315)		(1,462)
Unfunded Supplementary Pension Plans [Member]
Change in benefit obligation [Roll Forward]
Benefit obligation at end of year		11,000		11,400
Unfunded Stock Balance [Member] | Nonemployee Directors [Member]
Change in benefit obligation [Roll Forward]
Benefit obligation at end of year		$ 100		$ 100

[1] (c) Excludes dividends and interest receivable totaling $314,000 and $335,000 at December 31, 2014 and 2013, respectively.