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Derivative Instruments (Narrative) (Details) - USD ($) | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2026 | Dec. 31, 2025 | Dec. 31, 2021
Derivative [Line Items] |  |  |  |
Derivative, Notional Amount |  | $ 5,182,136,000 | $ 4,593,942,000 |
Derivative Asset | [1] | 58,399,000 | 51,421,000 |
Fair Value Hedging | Loans |  |  |  |
Derivative [Line Items] |  |  |  |
Carrying Value of Hedged Items |  | 136,300,000 |  |
Interest rate swaps |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Notional Amount |  | 2,063,942,000 | 1,968,679,000 |
Variation Margin Impact to Positive Fair Values of Cleared Swaps |  | 0 |  |
Interest rate swaps | Fair Value Hedging |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Notional Amount |  | 100,000,000.0 |  |
Interest Rate Floor [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Notional Amount |  | $ 2,500,000,000 | $ 2,000,000,000 |
Derivative, Description of Terms |  | As of March 31, 2026, the Company held five interest rate floors indexed to 1-month SOFR to hedge the risk of declining interest rates on certain floating rate commercial loans. The floors have a combined notional value of $2.5 billion. Each of the five interest rate floors has a six-year term and a notional amount of $500.0 million. In the event that the index rate falls below zero, the maximum rate that the Company can earn on the notional amount of each floor is limited to the strike rate. |  |
Derivative, Premium Paid |  | $ 102,200,000 |  |
Maximum Length of Time Hedged in Interest Rate Cash Flow Hedge |  | 6 years 6 months |  |
Unrealized gain (loss) on interest rate cash flow hedges, pretax, amount recorded in accumulated other comprehensive income |  | $ 24,900,000 |  |
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months |  | 14,000,000.0 |  |
Monetized Interest Rate Floor [Member] |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Notional Amount |  |  |  | $ 1,500,000,000
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months |  | 5,600,000 |  |
Derivative Asset |  |  |  | $ 163,200,000
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred |  | $ 5,600,000 |  |
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimate of Time to Transfer |  | 9 months |  |
March 24, 2026 Floor |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Premium Paid |  | $ 11,900,000 |  |
[1] | * The fair value of each class of derivative is shown in Note 12.

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- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. 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