Investments In Unconsolidated Subsidiaries (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended		6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011 ESNE [Member]	Mar. 31, 2011 Seneca Energy and Model City [Member]
Equity method investment ownership percentage			50.00%	50.00%
Sale of equity method investment	$ 59,365			$ 59,400
Gain on sale of equity method investment	$ 50,879	$ 0		$ 50,900

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 159
-Paragraph 18
-Subparagraph f

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 18
-Paragraph 20
-Subparagraph a (1)

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- Definition

Gain or loss on entity's disposition of equity in securities of subsidiaries or 50 percent or less owned persons. Reflects the difference in the parent company's carrying amount of the equity interest in the subsidiary (or equity method investee) immediately before and after all stock transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 13
-Subparagraph g
-Article 9

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- Definition

The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 15

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 16
-Subparagraph b

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