FAIR VALUES OF ASSETS AND LIABILITIES - Fair Value Option-Changes in Fair Value (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Fair Value, Recurring
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gains (losses) from fair value changes	$ 1	$ 5	$ 16	$ 2
Loans held for investment | Fair Value, Recurring
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gains (losses) from fair value changes	0	0	(1)	(1)
Long-term debt | Fair Value, Recurring
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gains (losses) from fair value changes	$ 0	$ (3)	$ (5)	$ (5)