v3.26.1
Investment Securities - Narrative (Details) - USD ($)
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Sep. 30, 2025
Jun. 30, 2025
Jun. 30, 2022
Sep. 30, 2021
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2022
Debt Securities, Available-for-sale [Line Items]                  
Debt securities, reclassified     $ 3,590,000,000            
Proceeds from sale of available-for-sale securities   $ 3,160,000,000              
Pre-tax loss   $ 625,600,000              
Income tax benefit related to security gains (losses) (as percent)   21.946%              
Debt securities, available-for-sale, transfer to held-to-maturity         $ 1,990,000,000 $ 500,800,000      
Available-for-sale, transfer to held-to-maturity, gain (loss)                 $ 0
Available for sale mortgage backed securities $ 3,439,526,000 $ 3,642,809,000         $ 3,439,526,000    
Available-for-sale, interest receivable 21,600,000           21,600,000    
Available-for-sale securities 3,077,181,000 3,266,221,000         3,077,181,000    
Securities valued at less than historical cost, amount $ 2,747,786,000 2,660,240,000         $ 2,747,786,000    
Securities valued at less than historical cost (as percent) 89.30%           89.30%    
Provision for credit losses, AFS securities $ 0     $ 0     $ 0 $ 0  
Securities pledged as collateral 1,830,000,000 2,040,000,000.00         1,830,000,000    
Realized gains 0     0     0 0  
Realized losses 0     $ 0     0 $ 0  
Variable rate commercial MBS                  
Debt Securities, Available-for-sale [Line Items]                  
Available for sale mortgage backed securities 562,500,000 597,400,000         562,500,000    
Residential Mortgage Backed Securities                  
Debt Securities, Available-for-sale [Line Items]                  
Available for sale mortgage backed securities $ 1,500,000,000 $ 1,600,000,000         $ 1,500,000,000