Significant Accounting Policies - Additional Cash Flow Information (Detail) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025
Accounting Policies [Abstract]
Interest	$ 288,523	$ 347,183
U.S. federal income taxes, net of refunds received	66,500	63,500
State income/franchise taxes, net of refunds received	1,547	1,806
Unsettled securities transactions	95,471	89,045
Loans foreclosed and transferred to other real estate owned and foreclosed assets	218	0
Loans transferred to loans held for sale	9,421	0
Right-of-use lease assets obtained in exchange for lessee operating lease liabilities	$ 6,894	$ 10,623

No definition available.

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Amount, after income tax refund received, of cash paid to federal (national) tax jurisdiction for tax on income.

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Amount, after income tax refund received, of cash paid to state and local tax jurisdictions for tax on income.

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The increase (decrease) during the reporting period in the aggregate amount of obligations incurred arising from transactions with broker-dealers, such as amounts due on margin and unsettled cash transactions; includes payables to brokers, dealers and clearing organizations.

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Amount of cash paid for interest, including, but not limited to, capitalized interest and payment to settle zero-coupon bond attributable to accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount; classified as operating and investing activities.

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Amount of increase in right-of-use asset obtained in exchange for operating lease liability.

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Value of loans and leases held in the entity's portfolio transferred to loans and leases held-for-sale in noncash transactions.

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Value transferred from mortgage loans to real estate owned (REO) in noncash transactions.

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