Securities - Narrative (Details)	2 Months Ended	3 Months Ended			9 Months Ended
	Jul. 31, 2024 USD ($)	Sep. 30, 2025 USD ($) investment	Mar. 31, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) investment	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($) investment	Dec. 31, 2009 USD ($)
Debt Securities, Available-for-sale [Line Items]
Proceeds from sale of short-term investments			$ 204,900,000
Proceeds from Sales	$ 375,300,000	$ 500,000		$ 175,738,000	$ 205,876,000	$ 402,105,000
Realized gain (loss) on sale of available-for-sale securities	$ (34,900,000)
Tax equivalent yield (as a percent)	3.12%
Tax equivalent yield period (in years)	7 years
Carrying value of securities pledged to secure repurchase agreements, public and trust deposits and other by law		998,737,000			998,737,000		$ 1,065,880,000
Securities, available-for-sale, at fair value, allowance for credit losses		0			0		0
Accrued interest receivable on available-for-sale debt securities		8,015,000			8,015,000		8,110,000
Original amount in non-controlling investment security in a single banking organization		353,000			353,000		$ 353,000	$ 1,350,000
Additional impairment on equity securities recognized through earnings		$ 0			$ 0			$ 997,000
Equity Securities
Debt Securities, Available-for-sale [Line Items]
Number of non-controlling investments in a single banking organization | investment		1			1		1