Business Combination (Tables)

12 Months Ended

Dec. 31, 2011

Subsequent Event [Abstract]

Schedule of Purchase Price Allocation [Table Text Block]

The acquisition described above was accounted for as a business combination. The purchase price shown below is preliminary and has been allocated to the identifiable assets acquired and liabilities assumed based on the estimated fair values at the acquisition date using a third-party valuation expert. Any amount not allocated to identifiable assets and liabilities was allocated to goodwill. These allocations may change in subsequent financial statements. Enogex is currently evaluating the preliminary purchase price allocation, which will be adjusted as additional information relative to the fair value of assets and liabilities becomes available. Enogex expects the purchase price allocations to be completed by the end of the first quarter of 2012. The following table summarizes the preliminary purchase price allocation for this acquisition.

(In millions)
Current assets	$	5.4
Net property, plant and equipment	24.3
Intangible assets	136.3
Goodwill	39.4
Current liabilities assumed	(5.0		)
Total	$	200.4