ACQUISITION (Details) (USD $)	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
ACQUISITION [Abstract]
Revenues Contributed By Acquired Entity	$ 100,600,000		$ 594,000,000
Net income (loss) contributed by acquired entity	(6,200,000)		29,700,000
Final indebtedness and working capital adjustment			11,200,000
Period after acquisition to finalize the allocation of consideration transferred			1
Allocation of purchase price [Abstract]
Current assets	310,800,000		310,800,000
Noncurrent assets	1,418,900,000		1,418,900,000
Current liabilities	(167,900,000)		(167,900,000)
Long-term debt	(397,400,000)		(397,400,000)
Other noncurrent liabilities	(559,100,000)		(559,100,000)
Preferred stock	(800,000)		(800,000)
Total identifiable net assets	604,500,000		604,500,000
Goodwill	302,200,000		302,200,000
Total Purchase Price, Net	906,700,000		906,700,000
Increase in goodwill due to finalizing purchase price allocation			3,300,000
Increase in goodwill due to working capital adjustment			1,600,000
Increase in goodwill due to adjustments to the values of assets and liabilities recognized			1,700,000
Pro forma information [Abstract]
Pro forma operating revenues		342,547,000		1,216,976,000
Pro forma operating expenses		308,329,000		1,316,593,000
Pro forma net income (loss)		12,634,000		(197,073,000)
Pro forma earnings per share of common stock - basic (in dollars per share)		$ 0.25		$ (3.90)
Pro-forma net income, excluding goodwill impairment charges		$ 12,600,000		$ 74,100,000
Pro-forma earnings per share, excluding goodwill impairment charges (in dollars per share)		$ 0.25		$ 1.47

The net assets acquired and liabilities assumed of the acquired entity, excluding goodwill.

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The amount of acquisition cost of a business combination allocated to preferred stock of the acquired entity.

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The amount of final indebtedness and working capital adjustment of the purchase price.

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Purchase accounting adjustments due to adjustments to the values of assets and liabilities recognized in the Acquisition, needed to revise the carrying amount of goodwill to fair value.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the gas companies.

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The period (in years) after Acquisition to finalize the allocation of consideration transferred.

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The pro forma earnings per share for the period, excluding goodwill impairment charges, as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma net Income or Loss for the period, excluding goodwill impairment charges, as if the business combination or combinations had been completed at the beginning of a period.

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Aggregate gas revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains.

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The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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The total purchase price of the acquired entity. This includes cash paid to equity interest holders of the acquired entity, fair value of debt and equity securities issued to equity holders of the acquired entity, and transaction costs paid to third parties to consummate the acquisition.

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The amount of acquisition cost of a business combination allocated to current assets.

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The amount of acquisition cost of a business combination allocated to current liabilities of the acquired entity.

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Amount of goodwill arising from a business combination, which is the excess of the cost of the acquired entity over the amounts assigned to assets acquired and liabilities assumed.

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The amount of acquisition cost of a business combination allocated to noncurrent assets.

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The amount of acquisition cost of a business combination allocated to the noncurrent portion of the long-term debt assumed from the acquired entity.

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The amount of acquisition cost of a business combination allocated to other noncurrent liabilities of the acquired entity.

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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Purchase accounting adjustments needed to revise the carrying amount of goodwill to fair value.

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