v3.25.1
Fair value measurement - Assets and liabilities measured at fair value on a recurring basis (Details) - USD ($)
$ in Thousands
Mar. 31, 2025
Dec. 31, 2024
Mar. 31, 2024
Dec. 31, 2023
Assets        
Debt securities available-for-sale $ 19,493,180 $ 18,245,903    
Mortgage servicing rights 104,743 108,103 $ 114,964 $ 118,109
US Treasury Securities        
Assets        
Debt securities available-for-sale 14,273,968 12,995,110    
Collateralized Mortgage Obligations - Federal agencies        
Assets        
Debt securities available-for-sale 115,859 120,284    
Other        
Assets        
Debt securities available-for-sale 750 2,250    
Recurring        
Assets        
Debt securities available-for-sale 19,493,180 18,245,903    
Trading account debt securities, excluding derivatives 28,477 32,783    
Equity securities at fair value 45,536 46,045    
Mortgage servicing rights 104,743 108,103    
Loans held-for-sale 5,077 5,423    
Derivatives 20,828 26,023    
Total assets measured at fair value on a recurring basis 19,697,841 18,464,280    
Liabilities        
Derivatives (19,523) (22,832)    
Total (19,523) (22,832)    
Recurring | US Treasury Securities        
Assets        
Debt securities available-for-sale 14,273,968 12,995,110    
Trading account debt securities, excluding derivatives 8,534 2,824    
Recurring | Obligations of Puerto Rico, States and political subdivisions        
Assets        
Trading account debt securities, excluding derivatives 53 55    
Recurring | Collateralized Mortgage Obligations - Federal agencies        
Assets        
Debt securities available-for-sale 115,859 120,284    
Recurring | CMO        
Assets        
Trading account debt securities, excluding derivatives 636 655    
Recurring | Mortgage Backed Securities        
Assets        
Debt securities available-for-sale 5,102,603 5,128,259    
Trading account debt securities, excluding derivatives 19,127 29,116    
Recurring | Other        
Assets        
Debt securities available-for-sale 750 2,250    
Trading account debt securities, excluding derivatives 127 133    
Recurring | Level 1        
Assets        
Debt securities available-for-sale 8,601,447 7,512,171    
Trading account debt securities, excluding derivatives 8,524 2,814    
Equity securities at fair value 0 0    
Mortgage servicing rights 0 0    
Loans held-for-sale 0 0    
Derivatives 0 0    
Total assets measured at fair value on a recurring basis 8,609,971 7,514,985    
Liabilities        
Derivatives 0 0    
Total 0 0    
Recurring | Level 1 | US Treasury Securities        
Assets        
Debt securities available-for-sale 8,601,447 7,512,171    
Trading account debt securities, excluding derivatives 8,524 2,814    
Recurring | Level 1 | Obligations of Puerto Rico, States and political subdivisions        
Assets        
Trading account debt securities, excluding derivatives 0 0    
Recurring | Level 1 | Collateralized Mortgage Obligations - Federal agencies        
Assets        
Debt securities available-for-sale 0 0    
Recurring | Level 1 | CMO        
Assets        
Trading account debt securities, excluding derivatives 0 0    
Recurring | Level 1 | Mortgage Backed Securities        
Assets        
Debt securities available-for-sale 0 0    
Trading account debt securities, excluding derivatives 0 0    
Recurring | Level 1 | Other        
Assets        
Debt securities available-for-sale 0 0    
Trading account debt securities, excluding derivatives 0 0    
Recurring | Level 2        
Assets        
Debt securities available-for-sale 10,890,526 10,730,998    
Trading account debt securities, excluding derivatives 19,742 29,752    
Equity securities at fair value 45,129 45,664    
Mortgage servicing rights 0 0    
Loans held-for-sale 5,077 5,423    
Derivatives 20,828 26,023    
Total assets measured at fair value on a recurring basis 10,981,302 10,837,860    
Liabilities        
Derivatives (19,523) (22,832)    
Total (19,523) (22,832)    
Recurring | Level 2 | US Treasury Securities        
Assets        
Debt securities available-for-sale 5,672,521 5,482,939    
Trading account debt securities, excluding derivatives 10 10    
Recurring | Level 2 | Obligations of Puerto Rico, States and political subdivisions        
Assets        
Trading account debt securities, excluding derivatives 53 55    
Recurring | Level 2 | Collateralized Mortgage Obligations - Federal agencies        
Assets        
Debt securities available-for-sale 115,859 120,284    
Recurring | Level 2 | CMO        
Assets        
Trading account debt securities, excluding derivatives 636 655    
Recurring | Level 2 | Mortgage Backed Securities        
Assets        
Debt securities available-for-sale 5,102,146 5,127,775    
Trading account debt securities, excluding derivatives 19,043 29,032    
Recurring | Level 2 | Other        
Assets        
Debt securities available-for-sale 0 0    
Trading account debt securities, excluding derivatives 0 0    
Recurring | Level 3        
Assets        
Debt securities available-for-sale 1,207 2,734    
Trading account debt securities, excluding derivatives 211 217    
Equity securities at fair value 0 0    
Mortgage servicing rights 104,743 108,103    
Loans held-for-sale 0 0    
Derivatives 0 0    
Total assets measured at fair value on a recurring basis 106,161 111,054    
Liabilities        
Derivatives 0 0    
Total 0 0    
Recurring | Level 3 | US Treasury Securities        
Assets        
Debt securities available-for-sale 0 0    
Trading account debt securities, excluding derivatives 0 0    
Recurring | Level 3 | Obligations of Puerto Rico, States and political subdivisions        
Assets        
Trading account debt securities, excluding derivatives 0 0    
Recurring | Level 3 | Collateralized Mortgage Obligations - Federal agencies        
Assets        
Debt securities available-for-sale 0 0    
Recurring | Level 3 | CMO        
Assets        
Trading account debt securities, excluding derivatives 0 0    
Recurring | Level 3 | Mortgage Backed Securities        
Assets        
Debt securities available-for-sale 457 484    
Trading account debt securities, excluding derivatives 84 84    
Recurring | Level 3 | Other        
Assets        
Debt securities available-for-sale 750 2,250    
Trading account debt securities, excluding derivatives 127 133 $ 166  
Recurring | NAV        
Assets        
Debt securities available-for-sale 0 0    
Trading account debt securities, excluding derivatives 0 0    
Equity securities at fair value 407 381    
Mortgage servicing rights 0 0    
Loans held-for-sale 0 0    
Derivatives 0 0    
Total assets measured at fair value on a recurring basis 407 381    
Liabilities        
Derivatives 0 0    
Total 0 0    
Recurring | NAV | US Treasury Securities        
Assets        
Debt securities available-for-sale 0 0    
Trading account debt securities, excluding derivatives 0 0    
Recurring | NAV | Obligations of Puerto Rico, States and political subdivisions        
Assets        
Trading account debt securities, excluding derivatives 0 0    
Recurring | NAV | Collateralized Mortgage Obligations - Federal agencies        
Assets        
Debt securities available-for-sale 0 0    
Recurring | NAV | CMO        
Assets        
Trading account debt securities, excluding derivatives 0 0    
Recurring | NAV | Mortgage Backed Securities        
Assets        
Debt securities available-for-sale 0 0    
Trading account debt securities, excluding derivatives 0 0    
Recurring | NAV | Other        
Assets        
Debt securities available-for-sale 0 0    
Trading account debt securities, excluding derivatives $ 0 $ 0