Investment Securities - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2026	Dec. 31, 2025
Additional disclosures
Other investment securities	$ 0
Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssets
Additional disclosures
Accrued interest receivable for investment securities	45,800	$ 38,900
Asset Pledged as Collateral
Additional disclosures
Investment securities market value	4,800,000	5,200,000
Carrying value of public fund deposits	5,200,000	5,500,000
Asset Pledged as Collateral \| Public Funds Deposits
Additional disclosures
Carrying value of public fund deposits	5,100,000	5,200,000
Asset Pledged as Collateral \| FHLB Advances
Additional disclosures
Carrying value of public fund deposits	22,400	182,200
Asset Pledged as Collateral \| Interest rate swap
Additional disclosures
Carrying value of public fund deposits	$ 73,800	$ 83,300

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Interest, dividends, rents, ancillary and other revenues earned but not yet received by the entity on its investments.

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Amount of impairment loss on investment in equity security without readily determinable fair value.

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Amount of investment in marketable security.

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