BORROWINGS - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	9 Months Ended
BORROWINGS - Narrative (Details) - USD ($) $ in Millions	Oct. 31, 2026	Sep. 30, 2026	Dec. 31, 2025
Debt Instrument [Line Items]
Total borrowings and other debt obligations		$ 42,816	$ 37,102
SDART Platform
Debt Instrument [Line Items]
On-balance sheet securitization transaction		1,900
On-balance sheet securitization transaction, retained		308
SDART Platform \| Subsequent Event
Debt Instrument [Line Items]
On-balance sheet securitization transaction	$ 1,200
On-balance sheet securitization transaction, retained	$ 86
CLNs due January 2039
Debt Instrument [Line Items]
Debt issued		325
CLNs due January 2039 \| Subsidiaries
Debt Instrument [Line Items]
Debt instrument, reference pool		$ 1,500
Basis spread (as a percent)		5.25%
CLNs Due July 2034
Debt Instrument [Line Items]
Debt issued		$ 280
CLNs Due July 2034 \| Subsidiaries
Debt Instrument [Line Items]
Debt instrument, reference pool		$ 2,600
Basis spread (as a percent)		6.09%
CLNs Due November 2035
Debt Instrument [Line Items]
Debt issued		$ 694
CLNs Due November 2035 \| Subsidiaries
Debt Instrument [Line Items]
Debt instrument, reference pool		$ 3,600
Basis spread (as a percent)		6.84%
Senior Notes Due 2029 \| Senior Notes
Debt Instrument [Line Items]
Basis spread (as a percent)		1.05%
Senior Notes Due 2030 \| Senior Notes
Debt Instrument [Line Items]
Basis spread (as a percent)		1.19%
5.04% Senior Notes Due June 2030 \| Senior Notes
Debt Instrument [Line Items]
Debt issued		$ 1,000
Stated interest rate		5.04%
5.22% Senior Notes Due June 2032 \| Senior Notes
Debt Instrument [Line Items]
Debt issued		$ 750
Stated interest rate		5.22%
5.70% Senior Notes Due June 2037 \| Senior Notes
Debt Instrument [Line Items]
Debt issued		$ 750
Stated interest rate		5.70%
Floating Rate Senior Notes due August 2029 \| Senior Notes
Debt Instrument [Line Items]
Debt issued		$ 1,000
Floating Rate Senior Notes due August 2030 \| Senior Notes
Debt Instrument [Line Items]
Debt issued		$ 1,000