FINANCIAL INSTRUMENTS (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
Accumulated net loss from designated or qualifying cash flow hedges	$ 7,400,000	$ 7,700,000
Net amount of deferred gains and losses on cash flow hedges that is expected to be reclassified within the next 12 months	1,300,000
Notional amount of foreign currency forward contracts	34,400,000
Fair Value Hedging [Member]
Fair Value hedges - fixed-to-variable interest rate swaps	550,000,000
Asset [Member]
Derivative, Fair Value, Net	51,286,000	55,052,000
Interest Rate Swaps [Member]
Derivative asset designated as hedging instrument fair value	51,300,000	56,500,000
Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member] | Other assets [Member]
Total Net Derivatives Asset	51,265,000	56,520,000
Not Designated as Hedging Instrument [Member] | Foreign Currency Forward Contracts [Member] | Other current assets [Member]
Total Net Derivatives Asset	482,000	180,000
Not Designated as Hedging Instrument [Member] | Foreign Currency Forward Contracts [Member] | Other current liabilities [Member]
Total Net Derivatives Liabilities	$ 461,000	$ 1,648,000
Minimum [Member] | Fair Value Hedging [Member]
Variable interest rate	0.54%
Maximum [Member] | Fair Value Hedging [Member]
Variable interest rate	1.33%