Acquisitions and Sales of Other Assets (Purchase Price Allocation) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Jul. 02, 2012
Significant Acquisitions and Disposals [Line Items]
Goodwill	$ 16,340	$ 16,365
Total estimated purchase price			18,071
Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Current assets			3,204
Property, plant and equipment			23,141
Goodwill			12,469
Other long-term assets, excluding goodwill			9,990
Total assets			48,804
Current liabilities, including current maturities of long-term debt			3,593
Long-term liabilities, preferred stock and noncontrolling interests			10,394
Long-term debt			16,746
Total liabilities and preferred stock			30,733
Total estimated purchase price			$ 18,071