Overview & Summary of Significant Accounting Policies - Schedule of Disaggregation of Revenue by Major Source (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation Of Revenue [Line Items]
Revenues	$ 25,182	$ 23,350	$ 71,983	$ 71,606
Total revenues from sales and services
Disaggregation Of Revenue [Line Items]
Revenues	24,588	22,718	70,194	69,577
Automotive sales
Disaggregation Of Revenue [Line Items]
Revenues	18,831	18,582	53,821	57,879
Automotive regulatory credits
Disaggregation Of Revenue [Line Items]
Revenues	739	554	2,071	1,357
Energy generation and storage sales
Disaggregation Of Revenue [Line Items]
Revenues	2,228	1,416	6,616	4,188
Services and other
Disaggregation Of Revenue [Line Items]
Revenues	2,790	2,166	7,686	6,153
Automotive leasing
Disaggregation Of Revenue [Line Items]
Revenues	446	489	1,380	1,620
Energy generation and storage leasing
Disaggregation Of Revenue [Line Items]
Revenues	$ 148	$ 143	$ 409	$ 409