DERIVATIVE FINANCIAL INSTRUMENTS (Details 2) (Cash flow hedges, USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Gain (Loss) on Derivatives in Cash Flow Hedging Relationship
Expected reclassification out of accumulated other comprehensive income (loss) into earnings during the next twelve months			$ 2,700,000
Inflation
Gain (Loss) on Derivatives in Cash Flow Hedging Relationship
Gain (loss) recognized in other comprehensive income (loss) (effective portion)	(5,907,000)	(9,314,000)	2,184,000	(3,892,000)
Gain (loss) reclassified from accumulated other comprehensive income (loss) into income (effective portion)	(250,000)	(463,000)	(1,328,000)	(1,084,000)
Gain (loss) recognized in income (ineffective portion)	(617,000)	(696,000)	28,000	(336,000)
Interest rate swaps
Gain (Loss) on Derivatives in Cash Flow Hedging Relationship
Gain (loss) recognized in other comprehensive income (loss) (effective portion)	(248,000)	(858,000)	(343,000)	(2,116,000)
Gain (loss) reclassified from accumulated other comprehensive income (loss) into income (effective portion)	$ (895,000)	$ (1,982,000)	$ (1,778,000)	$ (3,973,000)