v3.26.1
BORROWINGS - Schedule of Subordinated Debt (Details)
$ in Millions
 3 Months Ended
Mar. 31, 2026
USD ($)
Debt Instrument [Line Items]  
Aggregate Principal Amount Issued $ 645
Net proceeds 641
Carrying Value 641
Senior Notes  
Debt Instrument [Line Items]  
Aggregate Principal Amount Issued 500
Net proceeds 497
Carrying Value 498
Other Subordinated Debt  
Debt Instrument [Line Items]  
Aggregate Principal Amount Issued 145
Net proceeds 144
Carrying Value $ 143
Subordinated Notes Due 2030 | Senior Notes  
Debt Instrument [Line Items]  
Interest Rate 5.722%
Aggregate Principal Amount Issued $ 500
Net proceeds 497
Carrying Value $ 498
Subordinated Notes Due 2030 | Other Subordinated Debt  
Debt Instrument [Line Items]  
Basis points, interest rate, type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) [Member]
Basis points, spread 1.93%
Fixed-To-Floating Rate Subordinated Notes due 2029 | Other Subordinated Debt  
Debt Instrument [Line Items]  
Interest Rate 6.314%
Aggregate Principal Amount Issued $ 120
Net proceeds 118
Carrying Value $ 119
Basis points, interest rate, type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) [Member]
Basis points, spread 2.40%
Basis points, tenor spread adjustment 0.0026
Fixed-To-Floating Rate Subordinated Notes due December 6, 2028 | Other Subordinated Debt  
Debt Instrument [Line Items]  
Interest Rate 6.951%
Aggregate Principal Amount Issued $ 25
Net proceeds 26
Carrying Value $ 24
Basis points, interest rate, type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) [Member]
Basis points, spread 3.02%
Basis points, tenor spread adjustment 0.0026