v3.26.1
Fair Value Measurements, Fair Value Of Financial Instruments as Measured On a Recurring Basis (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Assets: [Abstract]        
Trading securities $ 5,652,162 $ 5,392,745    
Available-for-sale securities 13,539,565 13,606,625    
Fair value option securities 178,098 102,096    
Mortgage servicing rights 333,381 322,724 $ 342,111 $ 338,145
Derviative contracts, net of cash collateral, Assets, Fair value 782,985 300,775    
Liabilities: [Abstract]        
Derivative contracts, net of cash collateral, Liabilities, Fair Value 282,590 397,573    
U.S. government securities [Member]        
Assets: [Abstract]        
Trading securities 6,379 9,237    
Residential agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Trading securities 5,513,068 5,307,849    
Available-for-sale securities 9,631,722 9,598,627    
Fair value option securities 165,706 102,096    
Municipal securities [Member]        
Assets: [Abstract]        
Trading securities 84,981 39,233    
Available-for-sale securities 175,123 184,273    
U.S. Treasury [Member]        
Assets: [Abstract]        
Available-for-sale securities 984 980    
Residential non-agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Available-for-sale securities 717,068 696,028    
Commercial agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Available-for-sale securities 3,014,195 3,126,244    
Fair value option securities 12,392 0    
Other debt securities [Member]        
Assets: [Abstract]        
Trading securities 47,734 36,426    
Available-for-sale securities 473 473    
Fair Value, Recurring [Member]        
Assets: [Abstract]        
Trading securities 5,652,162 5,392,745    
Available-for-sale securities 13,539,565 13,606,625    
Fair value option securities 178,098      
Residential mortgage loans held for sale 104,873 [1] 94,630 [2]    
Mortgage servicing rights 333,381 [3] 322,724 [4]    
Derviative contracts, net of cash collateral, Assets, Fair value 782,985 [5] 300,775 [6]    
Liabilities: [Abstract]        
Derivative contracts, net of cash collateral, Liabilities, Fair Value 282,590 [5] 397,573 [6]    
Fair Value, Recurring [Member] | U.S. government securities [Member]        
Assets: [Abstract]        
Trading securities 6,379 9,237    
Fair Value, Recurring [Member] | Residential agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Trading securities 5,513,068 5,307,849    
Available-for-sale securities 9,631,722 9,598,627    
Fair value option securities 165,706 102,096    
Fair Value, Recurring [Member] | Municipal securities [Member]        
Assets: [Abstract]        
Trading securities 84,981 39,233    
Available-for-sale securities 175,123 184,273    
Fair Value, Recurring [Member] | U.S. Treasury [Member]        
Assets: [Abstract]        
Available-for-sale securities 984 980    
Fair Value, Recurring [Member] | Residential non-agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Available-for-sale securities 717,068 696,028    
Fair Value, Recurring [Member] | Commercial agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Available-for-sale securities 3,014,195 3,126,244    
Fair value option securities 12,392      
Fair Value, Recurring [Member] | Other debt securities [Member]        
Assets: [Abstract]        
Trading securities 47,734 36,426    
Available-for-sale securities 473 473    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]        
Assets: [Abstract]        
Trading securities 0 0    
Available-for-sale securities 984 980    
Fair value option securities 0      
Residential mortgage loans held for sale 0 [1] 0 [2]    
Mortgage servicing rights 0 [3] 0 [4]    
Derviative contracts, net of cash collateral, Assets, Fair value 1,474 [5] 1,022 [6]    
Liabilities: [Abstract]        
Derivative contracts, net of cash collateral, Liabilities, Fair Value 3,250 [5] 12 [6]    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. government securities [Member]        
Assets: [Abstract]        
Trading securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Residential agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Trading securities 0 0    
Available-for-sale securities 0 0    
Fair value option securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal securities [Member]        
Assets: [Abstract]        
Trading securities 0 0    
Available-for-sale securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Treasury [Member]        
Assets: [Abstract]        
Available-for-sale securities 984 980    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Residential non-agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Available-for-sale securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Available-for-sale securities 0 0    
Fair value option securities 0      
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other debt securities [Member]        
Assets: [Abstract]        
Trading securities 0 0    
Available-for-sale securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]        
Assets: [Abstract]        
Trading securities 5,652,162 5,392,745    
Available-for-sale securities 13,538,108 13,605,172    
Fair value option securities 178,098      
Residential mortgage loans held for sale 97,972 [1] 88,335 [2]    
Mortgage servicing rights 0 [3] 0 [4]    
Derviative contracts, net of cash collateral, Assets, Fair value 781,511 [5] 299,753 [6]    
Liabilities: [Abstract]        
Derivative contracts, net of cash collateral, Liabilities, Fair Value 279,340 [5] 397,561 [6]    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. government securities [Member]        
Assets: [Abstract]        
Trading securities 6,379 9,237    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Trading securities 5,513,068 5,307,849    
Available-for-sale securities 9,631,722 9,598,627    
Fair value option securities 165,706 102,096    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal securities [Member]        
Assets: [Abstract]        
Trading securities 84,981 39,233    
Available-for-sale securities 175,123 184,273    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Treasury [Member]        
Assets: [Abstract]        
Available-for-sale securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential non-agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Available-for-sale securities 717,068 696,028    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Available-for-sale securities 3,014,195 3,126,244    
Fair value option securities 12,392      
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other debt securities [Member]        
Assets: [Abstract]        
Trading securities 47,734 36,426    
Available-for-sale securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]        
Assets: [Abstract]        
Trading securities 0 0    
Available-for-sale securities 473 473    
Fair value option securities 0      
Residential mortgage loans held for sale 6,901 [1] 6,295 [2]    
Mortgage servicing rights 333,381 [3] 322,724 [4]    
Derviative contracts, net of cash collateral, Assets, Fair value $ 0 [5] $ 0 [6]    
Liquidity Discount on Mortgage Loans Qualifying for Sale to US Govt Agencies 83.36% 82.84%    
Liabilities: [Abstract]        
Derivative contracts, net of cash collateral, Liabilities, Fair Value $ 0 [5] $ 0 [6]    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. government securities [Member]        
Assets: [Abstract]        
Trading securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Residential agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Trading securities 0 0    
Available-for-sale securities 0 0    
Fair value option securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal securities [Member]        
Assets: [Abstract]        
Trading securities 0 0    
Available-for-sale securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Treasury [Member]        
Assets: [Abstract]        
Available-for-sale securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Residential non-agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Available-for-sale securities 0 0    
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial agency mortgage-backed securities [Member]        
Assets: [Abstract]        
Available-for-sale securities 0 0    
Fair value option securities 0      
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other debt securities [Member]        
Assets: [Abstract]        
Trading securities 0 0    
Available-for-sale securities $ 473 $ 473    
[1] Residential mortgage loans held for sale measured at fair value on a recurring basis using significant unobservable inputs (Level 3) consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards and are valued at 83.36% of the unpaid principal balance.
[2] Residential mortgage loans held for sale measured at fair value on a recurring basis using significant unobservable inputs (Level 3) consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards and are valued at 82.84% of the unpaid principal balance.
[3] A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 5, Mortgage Banking Activities.
[4] A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 5, Mortgage Banking Activities.
[5] See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset and liability positions that were valued based on quoted prices in active markets for identical instruments (Level 1) are primarily exchange-traded interest rate derivative contracts held for trading and internal risk management purposes.
[6] See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset and liability positions that were valued based on quoted prices in active markets for identical instruments (Level 1) are primarily exchange-traded interest rate derivative contracts held for trading and internal risk management purposes.