Note 3 - Merger with Nicor (Detail) - Preliminary Allocation of the Purchase Price (USD $) In Millions, unless otherwise specified	Jun. 30, 2012
Current assets	$ 932
Property, plant and equipment	3,202
Goodwill	1,395
Other noncurrent assets, excluding goodwill	900
Current liabilities	(1,170)
Long-term debt	(599)
Other noncurrent liabilities	(2,157)
Total purchase consideration	$ 2,503

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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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

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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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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Amount of acquisition cost of a business combination allocated to other noncurrent liabilities not separately disclosed.

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The amount of acquisition cost of a business combination allocated to property, plant and equipment to be used in ongoing operations.

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