v3.26.1
Investment Securities - Narrative (Details) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]    
Held to maturity securities, assets pledged $ 130,568,000,000 $ 133,969,000,000
Available for sale securities, assets pledged 62,467,000,000 62,357,000,000
Credit loss expense 0 0
Writedown to fair value 0 0
Available for sale, allowance for credit loss 0 0
Accrued interest receivable 381,000,000 386,000,000
Write-off of accrued interest receivable on available for sale and held to maturity securities 0 0
Asset Pledged as Collateral    
Debt Securities, Available-for-sale [Line Items]    
Held to maturity securities, assets pledged 3,933,000,000 1,270,000,000
Available for sale securities, assets pledged 760,000,000 281,000,000
Asset Pledged as Collateral | Interest rate swaps    
Debt Securities, Available-for-sale [Line Items]    
Available for sale securities, assets pledged 760,000,000 281,000,000
Federal Home Loan Bank Advances    
Debt Securities, Available-for-sale [Line Items]    
Fair value of pledged securities 12,700,000,000  
Collateral value of pledged securities 11,800,000,000  
Federal Reserve Bank Advances    
Debt Securities, Available-for-sale [Line Items]    
Fair value of pledged securities 28,900,000,000  
Collateral value of pledged securities 28,000,000,000.0  
Deposits    
Debt Securities, Available-for-sale [Line Items]    
Fair value of pledged securities 1,600,000,000  
Collateral value of pledged securities 1,600,000,000  
U.S. agency mortgage-backed securities    
Debt Securities, Available-for-sale [Line Items]    
Held to maturity securities, assets pledged 128,551,000,000 133,563,000,000
Available for sale securities, assets pledged 37,741,000,000 41,434,000,000
Held to maturity securities, allowance for credit loss 0 0
U.S. agency mortgage-backed securities | Asset Pledged as Collateral | Securities Sold under Agreements to Repurchase    
Debt Securities, Available-for-sale [Line Items]    
Held to maturity securities, assets pledged 4,400,000,000  
Held to maturity securities, assets pledged that may be sold, repledged, or utilized 3,900,000,000  
U.S. Treasury securities    
Debt Securities, Available-for-sale [Line Items]    
Held to maturity securities, assets pledged 2,017,000,000 406,000,000
Available for sale securities, assets pledged 11,951,000,000 11,364,000,000
Held to maturity securities, allowance for credit loss $ 0 $ 0