BENEFIT PLANS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Pension Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	$ 985	$ 848
Interest cost	1,029	1,098
Expected return on plan assets	(2,451)	(2,299)
Amortization of unrecognized net loss	1,007	922
Amortization of prior service cost	14	(37)
Net periodic benefit cost	584	532
Post-retirement Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	0	0
Interest cost	22	29
Expected return on plan assets	0	0
Amortization of unrecognized net loss	3	3
Amortization of prior service cost	(45)	(206)
Net periodic benefit cost	$ (20)	$ (174)