ACCUMULATED OTHER COMPREHENSIVE INCOME LOSS (Reclass) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013		Dec. 31, 2011
Other comprehensive income
OtherComprehensiveIncomeReclassificationOfDefinedBenefitPlansNetGainLossRecognizedInNetPeriodicBenefitCostBeforeTax	$ (143)	[1]
OtherComprehensiveIncomeLossAmortizationPensionAndOtherPostretirementBenefitPlansNetPriorServiceCostRecognizedInNetPeriodicBenefitCostBeforeTax	(4,112)	[1]
OtherComprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other PostretirementBenefit Plans Before Tax	(4,255)
Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans Tax	1,533
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax	$ (2,722)		$ (2,722)

[1]  These items are included in the computation of net periodic pension cost. See Note 11, Pension and Other Postretirement Benefit Plans.