FAIR VALUE MEASUREMENTS (Details 3) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Fair value disclosures
Current Maturities	$ (75,000)
Long-Term Debt, excluding Current Maturities	987,000	950,000
Carrying Amount
Fair value disclosures
Long-Term Debt	1,062,000	950,000
Current Maturities	(75,000)
Long-Term Debt, excluding Current Maturities	987,000	950,000
Estimated Fair Value
Fair value disclosures
Long-Term Debt	1,195,717	1,082,531
Current Maturities	(78,095)
Long-Term Debt, excluding Current Maturities	$ 1,117,622	$ 1,082,531