Fair Value Measurements Fair Value, Assets Measured on Nonrecurring Basis Using Unobservable Inputs (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring fair value losses	$ (75)	$ (61)
Fair Value Measurements Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring fair value losses	(64)	(46)
Fair Value Measurements Nonrecurring [Member] | Operating Lease Equipment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring fair value losses	(31)	(31)
Fair Value Measurements Nonrecurring [Member] | Property, Plant and Equipment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring fair value losses	(2)	(5)
Fair Value Measurements Nonrecurring [Member] | Other assets and Acquired intangible assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring fair value losses	(1)	(10)
Fair Value Measurements Nonrecurring [Member] | Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring fair value losses	(30)
Fair Value Measurements Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	112	66
Fair Value Measurements Nonrecurring [Member] | Level 3 [Member] | Market Approach Valuation Technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Operating Lease Equipment	89	54
Fair Value Measurements Nonrecurring [Member] | Level 3 [Member] | Income Approach Valuation Technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value	8
Other assets and Acquired intangible assets, Fair Value	14	12
Investments, Fair Value Disclosure	$ 1