v3.25.2
Related Party Transactions - Narrative (Details) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended
Mar. 31, 2025
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Related Party Transaction [Line Items]          
Revenues   $ 4,255,000,000 $ 3,918,000,000 $ 8,419,000,000 $ 7,729,000,000
Related party tax payment       $ 0 0
Line of Credit | General Motors | Five Year Revolving Credit Facility          
Related Party Transaction [Line Items]          
Debt instrument term 5 years     5 years  
Current borrowing capacity   10,000,000,000   $ 10,000,000,000  
Junior Subordinated Revolving Credit Facility | General Motors          
Related Party Transaction [Line Items]          
Line of credit facilities - GM related party facility   1,000,000,000.0   1,000,000,000.0  
Revolving Credit Facility          
Related Party Transaction [Line Items]          
Maximum borrowing capacity   12,000,000,000.0   12,000,000,000.0  
Revolving Credit Facility | Line of Credit | General Motors          
Related Party Transaction [Line Items]          
Maximum borrowing capacity   14,100,000,000   $ 14,100,000,000  
Revolving Credit Facility | Line of Credit | General Motors | Three Year Revolving Credit Facility          
Related Party Transaction [Line Items]          
Debt instrument term 3 years     3 years  
Current borrowing capacity   4,100,000,000   $ 4,100,000,000  
Revolving Credit Facility | Line of Credit | General Motors | 364 Day Revolving Credit Facilities          
Related Party Transaction [Line Items]          
Maximum borrowing capacity   2,000,000,000.0   $ 2,000,000,000.0  
Debt instrument term       364 days  
GM          
Related Party Transaction [Line Items]          
Revenues   $ 918,000,000 $ 934,000,000 $ 1,600,000,000 $ 1,700,000,000