v3.24.1.u1
INVESTMENT SECURITIES - Narrative (Details)
$ in Millions
3 Months Ended
Mar. 31, 2024
USD ($)
position
Dec. 31, 2023
USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]    
Book value $ 18,485 $ 18,302
Fair value $ 17,077 17,008
Maximum individual state general bond obligation as a percentage of total debt securities (percent) 1.00%  
Securities in unrealized loss positions, number of positions | position 1,685  
Securities, number of positions | position 2,100  
S&P AA- rating    
Financing Receivable, Credit Quality Indicator [Line Items]    
Percentage of debt securities considered to be of investment-grade (percent) 97.00%  
Dispositions | Gentiva Hospice    
Financing Receivable, Credit Quality Indicator [Line Items]    
Book value $ 379 379
Fair value $ 397 $ 398