FAIR VALUE MEASUREMENTS AND FINANCIAL INSTRUMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Current maturities of long-term debt	$ 0	$ (15,844)
Long-term debt, net of current maturities	(580,000)	(580,000)
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Current maturities of long-term debt	0	(15,844)
Long-term debt, net of current maturities	(580,000)	(580,000)
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Current maturities of long-term debt	0	(15,875)
Long-term debt, net of current maturities	$ (554,419)	$ (581,994)