v3.26.3
Derivative Financial Instruments - Fair Value by Balance Sheet Grouping (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items]    
Amortized cost $ 3,943,220 $ 2,982,228
Fair Value, Held-to-maturity 1,734,484 1,925,492
Fair Value Hedging [Member]    
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items]    
Amortized cost 1,586,924 1,719,962
Hedged Asset, Fair Value Hedge 22,173 10,866
Investment Securities Available for Sale [Member] | Fair Value Hedging [Member]    
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items]    
Amortized cost [1] 1,586,924 1,719,962
Hedged Asset, Fair Value Hedge [1] $ 22,173 $ 10,866
[1] These amounts were included in the amortized cost basis of closed portfolios of available-for-sale securities designated in hedging relationships in which the hedged item is the stated amount of assets in the closed portfolios anticipated to be outstanding for the designated hedge period. At September 30, 2026 and December 31, 2025, the amortized cost basis of the closed portfolios used in these hedging relationships was $1.6 billion and $1.7 billion, respectively. The cumulative basis adjustments associated with these hedging relationships were ($22.2) million and $10.9 million, respectively, of which $1.4 million and $1.5 million, respectively, related to discontinued hedging relationships. At September 30, 2026 and December 31, 2025, the notional amount of the designated hedged items was $700.0 million.