Revenue - Remaining Performance Obligation (Details) - Operating Segments - Automotive - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Vehicles, parts, and accessories
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue Performance Obligation Satisfied In Prior Period	$ 844	$ 903	$ 887
Vehicles, parts, and accessories | Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue Performance Obligation Payment Terms	30 days
Vehicles, parts, and accessories | Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue Performance Obligation Payment Terms	120 days
Extended service contracts
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract with Customer, Liability		4,000	3,800
Contract with Customer, Liability, Revenue Recognized		1,100
Capitalized Contract Cost, Net	$ 270	247
Capitalized Contract Cost, Amortization	$ 74	$ 73	$ 63
Extended service contracts | Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Extended service contracts | Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	120 months
Other revenue | Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years
Other revenue | Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 years