BENEFIT PLANS (Details) (USD $)	12 Months Ended	3 Months Ended
	Dec. 31, 2011	Mar. 31, 2012 Pension Plans, Defined Benefit [Member]	Mar. 31, 2011 Pension Plans, Defined Benefit [Member]	Mar. 31, 2012 Post-retirement Benefit Plans, Defined Benefit [Member]	Mar. 31, 2011 Post-retirement Benefit Plans, Defined Benefit [Member]
Net periodic benefit cost [Abstract]
Service cost		$ 848,000	$ 686,000	$ 0	$ 0
Interest cost		1,098,000	961,000	29,000	38,000
Expected return on plan assets		(2,299,000)	(1,767,000)	0	0
Amortization of unrecognized net loss		922,000	474,000	3,000	2,000
Amortization of prior service cost		(37,000)	(37,000)	(206,000)	(264,000)
Net periodic benefit cost		532,000	317,000	(174,000)	(224,000)
Plan assets of acquiree merged into pension plan	$ 20,500,000