FAIR VALUE MEASUREMENTS (Details) (USD $)
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12 Months Ended | 12 Months Ended | 12 Months Ended | ||||||||||||
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Dec. 31, 2011
Days
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Dec. 31, 2010
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Dec. 31, 2011
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Measurements, Recurring [Member]
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Dec. 31, 2010
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Measurements, Recurring [Member]
|
Dec. 31, 2011
Significant Other Observable Inputs (Level 2)
Fair Value, Measurements, Recurring [Member]
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Dec. 31, 2010
Significant Other Observable Inputs (Level 2)
Fair Value, Measurements, Recurring [Member]
|
Dec. 31, 2011
Significant Unobservable Inputs (Level 3)
Fair Value, Measurements, Recurring [Member]
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Dec. 31, 2010
Significant Unobservable Inputs (Level 3)
Fair Value, Measurements, Recurring [Member]
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Dec. 31, 2011
Total
Fair Value, Measurements, Recurring [Member]
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Dec. 31, 2010
Total
Fair Value, Measurements, Recurring [Member]
|
Dec. 31, 2011
Auction Rate Securities [Member]
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Dec. 31, 2011
Peak Energy Services Ltd.'s (Peak) [Member]
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Jun. 10, 2011
Peak Energy Services Ltd.'s (Peak) [Member]
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Dec. 31, 2011
Senior Notes [Member]
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Dec. 31, 2010
Senior Notes [Member]
|
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Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | |||||||||||||||
Temporary decline in fair value of securities | $ 500,000 | ||||||||||||||
Unrealized pre-tax gain (loss) on auction rate securities | 200,000 | ||||||||||||||
Interest rate, resetting days | 28 | ||||||||||||||
Auction rate securities | 4,245,000 | 5,437,000 | 0 | 0 | 0 | 0 | 4,245,000 | 5,437,000 | 4,245,000 | 5,437,000 | |||||
Marketable securities | 111,000 | 3,174,000 | 111,000 | 3,174,000 | 0 | 0 | 0 | 0 | 111,000 | 3,174,000 | |||||
Percentage of outstanding common shares of acquiree already owned by company (as a percent) | 3.15% | 3.15% | |||||||||||||
Long-term Debt, Fair Value | 538,500,000 | 278,300,000 | |||||||||||||
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 | 5,437,000 | 6,503,000 | |||||||||||||
Sale of auction rate securities at par | (1,000,000) | (1,300,000) | 1,000,000 | ||||||||||||
Unrealized gain (loss) included in other comprehensive income | (192,000) | 234,000 | |||||||||||||
Balance at the end of the period | $ 4,245,000 | $ 5,437,000 |