Restructuring and Other Initiatives - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Restructuring Cost and Reserve [Line Items]
Additions, interest accretion, and other	$ 1,155	$ 370	$ 2,225	$ 502
Restructuring payments	1,510	$ 541	3,938	$ 894
GMNA
Restructuring Cost and Reserve [Line Items]
Additions, interest accretion, and other					$ 7,900
Net of recoveries under cost sharing arrangement	660
Expected future cash impacts	1,600		2,500
GMNA \| Impairment and Other Charges
Restructuring Cost and Reserve [Line Items]
Additions, interest accretion, and other					3,200
GMNA \| Contract Termination
Restructuring Cost and Reserve [Line Items]
Additions, interest accretion, and other					4,700
GMNA \| EV Related Write Down
Restructuring Cost and Reserve [Line Items]
Restructuring payments			4,100		$ 400
GMNA \| Additional Net Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Additions, interest accretion, and other	2,300		3,400
GMNA \| Ongoing Commercial Negotiations
Restructuring Cost and Reserve [Line Items]
Additions, interest accretion, and other	1,300		1,000
GMNA \| Losses on Take-or-Pay Commitments
Restructuring Cost and Reserve [Line Items]
Additions, interest accretion, and other	1,100
GMNA \| Impaired Emissions Credits
Restructuring Cost and Reserve [Line Items]
Additions, interest accretion, and other	$ 493		$ 493