Investment Securities - Carrying Values of Investment Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Abstract]
Investment in subsidiary bank	$ 776,104	$ 551,354
Securities available for sale, Percent	100.00%	100.00%
U.S. Treasury
Debt Securities, Available-for-sale [Abstract]
Investment in subsidiary bank	$ 445,392	$ 243,925
Securities available for sale, Percent	57.39%	44.24%
Other securities (FHLB, FHLMC and FNMA)
Debt Securities, Available-for-sale [Abstract]
Investment in subsidiary bank	$ 31,934	$ 34,467
Securities available for sale, Percent	4.11%	6.25%
State and political subdivisions
Debt Securities, Available-for-sale [Abstract]
Investment in subsidiary bank	$ 248,582	$ 263,516
Securities available for sale, Percent	32.03%	47.80%
Mortgage-backed securities and collateralized mortgage obligations
Debt Securities, Available-for-sale [Abstract]
Investment in subsidiary bank	$ 50,196	$ 9,446
Securities available for sale, Percent	6.47%	1.71%