FAIR VALUE MEASUREMENTS (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Auction rate securities (i)	$ 4,354,000		$ 4,245,000
Marketable securities	11,778,000		111,000
Auction Rate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Temporary decline in fair value of securities	300,000
Unrealized pre-tax gain (loss) on auction rate securities	100,000
Senior secured notes
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Long-term Debt, Fair Value			538,500,000
Senior secured notes | Unsecured Senior Notes 2020
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Long-term Debt, Fair Value	816,000,000
Senior secured notes | Unsecured Senior Notes 2021
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Long-term Debt, Fair Value	623,500,000
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Auction rate securities (i)	0	[1]	0	[1]
Derivative instruments (ii)	0	[2]
Marketable securities	11,778,000	[3]	111,000	[3]
Derivative financial instruments (ii)	0	[2]
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Auction rate securities (i)	0	[1]	0	[1]
Derivative instruments (ii)	165,000	[2]
Marketable securities	0	[3]	0	[3]
Derivative financial instruments (ii)	1,242,000	[2]
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Auction rate securities (i)	4,354,000	[1]	4,245,000	[1]
Derivative instruments (ii)	0	[2]
Marketable securities	0	[3]	0	[3]
Derivative financial instruments (ii)	0	[2]
Changes in the entity's auction rate securities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Balance at the beginning of the period	4,245,000		5,437,000
Sale of auction rate securities at par	0		(1,000,000)
Unrealized gain (loss) included in other comprehensive income	109,000		(192,000)
Balance at the end of the period	4,354,000		4,245,000
Fair Value, Measurements, Recurring [Member] | Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Auction rate securities (i)	4,354,000	[1]	4,245,000	[1]
Derivative instruments (ii)	165,000	[2]
Marketable securities	11,778,000	[3]	111,000	[3]
Derivative financial instruments (ii)	$ 1,242,000	[2]

[1] The auction rate securities are classified as available-for-sale and the fair value of these securities was estimated utilizing a probability discounted cash flow analysis. As of December 31, 2012, all of the Company's auction rate securities continue to have AAA underlying ratings. The Company attributes the $0.3 million decline in the fair value of the securities from the original cost basis to external liquidity issues rather than credit issues. The Company assessed the decline in value to be temporary because it does not intend to sell and it is more likely than not that the Company will not have to sell the securities before their maturity. During the year ended December 31, 2012, the Company recorded an unrealized pre-tax gain of $0.1 million on its auction rate securities which is included in other comprehensive income.

[2] The fair value of derivatives is recorded based on the present value of cash flows using a crude oil forward rate curve.

[3] The fair value of marketable securities is recorded based on quoted market prices and changes in fair value were included in other comprehensive income.