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Inventories- Narrative (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
Inventories- Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Inventory [Line Items]
Total asset impairment charges	$ 3		$ 29		$ 3	$ 500
Restructuring charges	32	$ 34	96	$ 15
Employee Costs
Inventory [Line Items]
Restructuring charges	30	$ 31	90	$ 10
Motorparts
Inventory [Line Items]
Inventory write-down	44		82		44	82
Total asset impairment charges	1		16		1	16
Operating lease impairment			9			9
Motorparts \| Employee Costs
Inventory [Line Items]
Restructuring charges	1		$ 4		1	$ 4
Motorparts \| Other restructuring
Inventory [Line Items]
Restructuring charges	$ 3				$ 3