DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Derivative Instruments And Hedging Activities
Forward-starting interest rate swaps, unrealized gains (losses)	$ (9,604,000)	$ 8,619,000
5.300% Notes due October 15, 2014
Derivative Instruments And Hedging Activities
Debt instrument, stated percentage rate	5.30%
Interest rate Swap
Derivative Instruments And Hedging Activities
Forward-starting interest rate swaps, unrealized gains (losses)	(9,600,000)	8,600,000
Interest rate Swap | 4.625% Notes due July 15, 2013
Derivative Instruments And Hedging Activities
Number of forward-starting interest rate swaps	6
Derivative liability, notional amount	275,000,000
Interest rate Swap | 5.300% Notes due October 15, 2014
Derivative Instruments And Hedging Activities
Derivative liability, notional amount	275,000,000
Debt instrument, stated percentage rate	5.30%
Interest rate contracts and treasury lock agreements
Derivative Instruments And Hedging Activities
Interest rate swaps, expected net losses reclassified from accumulated other comprehensive loss to earnings over the next twelve months	$ 7,100,000