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Commitments and Contingencies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Commitments And Contingencies [Line Items]
Letters of credit outstanding	$ 520,200,000	$ 503,400,000
Mortgage loans sold	2,585,949,000	2,609,248,000	$ 1,963,214,000
Liability for estimated losses on repurchase and indemnification claims	578,000	188,000
Losses charged against liability	117,100	60,100
Unfunded commitments to investment partnerships	160,700,000	94,100,000
Commitments to invest in partnership for tax credits	126,300,000	67,000,000.0
Forward contracts
Commitments And Contingencies [Line Items]
Derivative instrument, contractual amounts	413,200,000	377,500,000
Commercial, commercial real estate, and construction loans | Commitments to extend credit
Commitments And Contingencies [Line Items]
Commitments to fund	11,800,000,000	11,500,000,000
Unused home equity lines | Commitments to extend credit
Commitments And Contingencies [Line Items]
Commitments to fund	1,000,000,000.0	999,100,000
Residential real estate | Commitments to extend credit
Commitments And Contingencies [Line Items]
Commitments to fund	$ 423,600,000	$ 361,300,000

X

- Definition

Nominal or face amount used to calculate payment on derivative.

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

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The cash inflow from sales of loans that are secured with real estate mortgages and are held with the intention to resell in the near future.

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Amount of commitment and contingent commitment, including amount of delayed equity contribution, for investment that generates income tax credit and other income tax benefit under tax credit program elected to be accounted for using proportional amortization method. Includes, but is not limited to, commitment and contingent commitment related to investment under tax credit program not meeting condition for accounting under proportional amortization method.

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Commitments and contingencies [Line Items].

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Liability for loss indemnification claims on residential mortgage loans previously sold to investors.

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Losses Charged Against Indemnification Liability

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Unfunded Commitments To Invest In Partnerships

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