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

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Acquisitions and Dispositions (Purchase Price Allocation) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Oct. 03, 2016	Dec. 31, 2015
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Goodwill	$ 19,425		$ 16,072
Piedmont Natural Gas [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Current assets		$ 497
Net property, plant and equipment		4,714
Goodwill		3,353
Other long-term assets		804
Total assets		9,368
Current liabilities, including current maturities of long-term debt		576
Long-term liabilities		1,790
Long-term debt		2,002
Total liabilities		4,368
Total purchase price		$ 5,000