Securities Available for Sale and Held to Maturity - Securities Held to Maturity by Credit Rating, as Determined by Moody's (Details) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Held to Maturity Amortized Cost		$ 1,426,279	$ 1,494,514
Aaa [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Held to Maturity Amortized Cost		1,425,939	1,490,004
Aaa1 to Aa3 [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Held to Maturity Amortized Cost		0	3,001
Not Rated [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities Held to Maturity Amortized Cost	[1]	$ 340	$ 1,509

[1] Not rated securities primarily consist of Mississippi municipal general obligations.