v3.26.3
Derivative Instruments and Hedging Activities - Narrative (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Jun. 30, 2026
Dec. 31, 2025
Dec. 22, 2025
Jun. 28, 2024
Derivative [Line Items]                
Loss protection fee percentage             4.94% 7.95%
Terminated cash flow hedge, unrealized gains in OCI         $ 8,000      
Reclassification adjustment for realized (gains) losses on cash flow hedges included in net income, net of tax $ 1,000 $ 0 $ 1,000 $ 0        
Pre-tax gain related to the amortization of terminated cash flow hedges     3,000          
Reclaim cash collateral 21,000   21,000     $ 36,000    
Obligation to return cash collateral 184,000   184,000     62,000    
Interest Rate Swap | Financial Institution Counterparties                
Derivative [Line Items]                
Notional amount 2,000,000   2,000,000          
Credit default swap | Residential Real Estate                
Derivative [Line Items]                
Notional amount             $ 80,000 $ 1,700,000
Credit default swap | Derivatives Not Designated as Hedging Instruments                
Derivative [Line Items]                
Notional amount $ 146,000   $ 146,000     $ 153,000 $ 80,000 $ 87,000
Derivative, notional amount, percent of reference pool             12.50% 5.00%
Credit Default Swap, Buying Protection | Derivatives Not Designated as Hedging Instruments                
Derivative [Line Items]                
Notional amount               $ 87,000