v3.26.1
DEBT SECURITIES - Available-for-Sale Investments Fair Value and Gross Unrealized Losses (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Schedule Of Available For Sale Securities [Line Items]        
Fair Value Less than 12 months $ 1,194,471 $ 221,766    
Unrealized Losses Less than 12 months 4,048 800    
Fair Value 12 months or more 2,748,359 2,962,174    
Unrealized Losses 12 months or more 353,173 353,583    
Total Fair Value 3,942,830 3,183,940    
Total Unrealized Losses 357,221 354,383    
Allowance for Credit Losses 839 763 $ 516 $ 521
U.S. Treasury and U.S. government agencies obligations [Member]        
Schedule Of Available For Sale Securities [Line Items]        
Fair Value Less than 12 months 484,473 91,584    
Unrealized Losses Less than 12 months 874 100    
Fair Value 12 months or more 673,704 796,505    
Unrealized Losses 12 months or more 17,539 20,730    
Total Fair Value 1,158,177 888,089    
Total Unrealized Losses 18,413 20,830    
Puerto Rico government obligations [Member]        
Schedule Of Available For Sale Securities [Line Items]        
Fair Value Less than 12 months 0 0    
Unrealized Losses Less than 12 months 0 0    
Fair Value 12 months or more 1,609 1,620    
Unrealized Losses 12 months or more 738 762    
Total Fair Value 1,609 1,620    
Total Unrealized Losses 738 762    
Allowance for Credit Losses 308 318 340 345
Residential MBS [Member]        
Schedule Of Available For Sale Securities [Line Items]        
Allowance for Credit Losses 531 445    
Residential MBS [Member] | U.S. Agencies MBS [Member]        
Schedule Of Available For Sale Securities [Line Items]        
Fair Value Less than 12 months 275,950 52,599    
Unrealized Losses Less than 12 months 1,221 148    
Fair Value 12 months or more 1,770,602 1,851,881    
Unrealized Losses 12 months or more 258,276 256,441    
Total Fair Value 2,046,552 1,904,480    
Total Unrealized Losses 259,497 256,589    
Allowance for Credit Losses 0 0    
Residential MBS [Member] | CMOs issued or guaranteed by the FHLMC, FNMA, and GNMA: [Member]        
Schedule Of Available For Sale Securities [Line Items]        
Fair Value Less than 12 months 423,478 74,773    
Unrealized Losses Less than 12 months 1,895 402    
Fair Value 12 months or more 163,247 170,490    
Unrealized Losses 12 months or more 39,938 38,897    
Total Fair Value 586,725 245,263    
Total Unrealized Losses 41,833 39,299    
Allowance for Credit Losses 0 0    
Residential MBS [Member] | Private label [Member]        
Schedule Of Available For Sale Securities [Line Items]        
Fair Value Less than 12 months 0 0    
Unrealized Losses Less than 12 months 0 0    
Fair Value 12 months or more 3,113 3,266    
Unrealized Losses 12 months or more 1,203 1,361    
Total Fair Value 3,113 3,266    
Total Unrealized Losses 1,203 1,361    
Allowance for Credit Losses 531 445 $ 176 $ 176
Commercial MBS [Member]        
Schedule Of Available For Sale Securities [Line Items]        
Fair Value Less than 12 months 10,570 2,810    
Unrealized Losses Less than 12 months 58 150    
Fair Value 12 months or more 136,084 138,412    
Unrealized Losses 12 months or more 35,479 35,392    
Total Fair Value 146,654 141,222    
Total Unrealized Losses 35,537 35,542    
Allowance for Credit Losses $ 0 $ 0