Fair Value Measurements Assets Fair Value Nonrecurring Basis (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair value of property, plant and equipment impaired during the period	$ 154	$ 53
Impairment of property, plant and equipment	201	27
Fair value of investments impaired during the period	0	10
Impairment of investments	0	5
Fair value of intangible assets impaired during the period	3	0
Impairment of intangible assets	2	0
Fair Value of Property, Goodwill Impaired During the Period	1,491	827
Impairment of goodwill	571	103
Fair value of assets held for sale impaired during the period	5	0
Impairment of assets held for sale	$ 14	$ 0