Investment Securities - Narrative (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2024 USD ($) security	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($) security
Investment securities total	$ 1,300,000		$ 1,200,000
Securities with no stated contractual date, fair value	75,156
Amortized cost	794,649		727,819
Available-for-sale Securities	691,076		628,829
Held-to-maturity securities	554,686		$ 585,052
Purchases of available-for-sale securities	138,443	$ 0
Maturities and paydowns of available-for-sale securities	72,110	47,550
Sales of available-for-sale securities	$ 0	0
Number of securities | security	223		230
Purchases of held-to-maturity securities	$ 0	2,452
Maturities and paydowns of held-to-maturity securities	$ 30,686	$ 34,891
Number of held-to-maturity securities in unrealized loss positions | security	155		123
Held-to-maturity investment securities pledged as collateral	$ 495,600		$ 559,300
Held-to-maturity investment securities held as collateral	0		0
Accrued interest receivable from available-for-sale investment securities	1,600		1,300
Accrued interest receivable from held-to-maturity investment securities	900		1,000
Other securities investments with no contractual maturity
Securities with no stated contractual date, amortized cost	700
Securities with no stated contractual date, fair value	700
Asset Pledged as Collateral
Available-for-sale Securities	0		0
Asset Pledged as Collateral | Federal Funds Purchased
Available-for-sale Securities	$ 284,800		$ 312,400
Financing Receivable, Pledging Purpose [Extensible Enumeration]	Noninterest-bearing Deposit Liabilities		Noninterest-bearing Deposit Liabilities