Acquisitions (Details) (USD $)	Sep. 30, 2011	Apr. 20, 2011 DPL Acquisition [Member] mw customers	Sep. 30, 2011 Senior Unsecured Note 7375 Due 2021 And Senior Secured Term Loan LIBOR Plus 325 [Member]
Business Acquisition [Line Items]
Total enterprise value of DPL acquisition		$ 4,700,000,000
Amount paid	3,500,000,000	3,500,000,000
Net debt portion of enterprise value of DPL acquisition		1,200,000,000
Customers Served		500,000
Generation Capacity Mega Watts		3,800
Recourse Debt Total			2,050,000,000
Business Acquisition Penalty Receivable From Acquiree For Early Rejection Of Merger Offer		$ 106,000,000

Fair Value of the liabilities incurred by the acquirer to former owners of the acquiree, including the fair value of any contingent consideration. If liabilities transferred as consideration remain within the combined entity after the business combination (for example, because the assets or liabilities were transferred to the acquiree rather than to its former owners), and the acquirer therefore retains control of them; in that situation, the acquirer measures those liabilities at their carrying amounts immediately before the acquisition date.

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