Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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+ Details

Goodwill (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Goodwill [Line Items]
Goodwill	$ 6,444	$ 6,441	$ 6,428
Regulated Distribution
Goodwill [Line Items]
Goodwill	5,025		5,025
Regulated Transmission
Goodwill [Line Items]
Goodwill	526		526
Competitive Energy Services
Goodwill [Line Items]
Goodwill	$ 893		$ 877