Acquisitions (Purchase Price Allocation) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$ 7,205,357us-gaap_Goodwill	$ 6,337,719us-gaap_Goodwill
Connecticut Operations [Member]
Business Acquisition [Line Items]
Current assets	73,631
Property, plant and equipment	1,450,057
Goodwill	867,638
Other intangibles - customer list	590,000
Other assets	336
Current liabilities	(101,590)
Deferred income taxes	(647,525)
Other liabilities	(214,760)
Total net assets acquired	$ 2,017,787

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Amount of assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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The amount of identifiable intangible assets recognized as of the acquisition date.

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Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.

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Amount of assets expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date.

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The amount of property, plant, and equipment recognized as of the acquisition date.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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