Property, Plant and Equipment (Depreciation Expense, Software Amortization and Capitalized Interest) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Depreciation expense (including amortization of assets recorded under capital leases)	$ 1,204,000,000	$ 1,193,000,000	$ 1,173,000,000
Amortization of internal-use software	33,000,000	36,000,000	45,000,000
Interest capitalized during development and construction	120,000,000	84,000,000	88,000,000
Property plant and equipment, net of accumulated depreciation mortgaged, pledged or subject to liens	$ 15,000,000,000	$ 15,000,000,000