Investment Securities - Additional Information (Details) - USD ($)	9 Months Ended
Sep. 30, 2024	Dec. 31, 2023
Additional disclosures
Carrying amount of the securities pledged to collateralize repurchase agreements	$ 7,077,128,000	$ 7,463,871,000
Other investment securities	0
Asset Pledged as Collateral
Additional disclosures
Investment securities market value	2,300,000,000	3,000,000,000.0
Carrying value of public fund deposits	2,500,000,000	3,200,000,000
Asset Pledged as Collateral \| Public Funds Deposits
Additional disclosures
Carrying value of public fund deposits	2,200,000,000	2,400,000,000
Asset Pledged as Collateral \| FHLB Advances
Additional disclosures
Carrying value of public fund deposits	207,500,000	729,400,000
Asset Pledged as Collateral \| Interest rate swap
Additional disclosures
Carrying value of public fund deposits	$ 106,900,000	$ 115,000,000.0

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

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Sum of the carrying amounts as of the balance sheet date of all investments.

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