Fair Value Measurements Fair Value, Assets Measured on Nonrecurring Basis Using Unobservable Inputs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring fair value losses	$ (34)	$ (20)
Fair Value Measurements Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring fair value losses	(34)	(20)
Fair Value Measurements Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	133	20
Operating Lease Equipment And Assets Held For Sale Or Re-Lease [Member] | Fair Value Measurements Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring fair value losses		(8)
Operating Lease Equipment And Assets Held For Sale Or Re-Lease [Member] | Fair Value Measurements Nonrecurring [Member] | Level 3 [Member] | Valuation, Market Approach [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		20
Property, Plant and Equipment [Member] | Fair Value Measurements Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring fair value losses	(1)
Property, Plant and Equipment [Member] | Fair Value Measurements Nonrecurring [Member] | Level 3 [Member] | Valuation, Income Approach [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	43
Investments [Member] | Fair Value Measurements Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nonrecurring fair value losses	(33)	(12)
Investments [Member] | Fair Value Measurements Nonrecurring [Member] | Level 3 [Member] | Valuation, Income Approach [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 90