Securities - Unrealized Gains (Losses) of Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Gross Unrealized Gains
Total unrealized gains (losses) on available-for-sale debt securities	$ 623	$ 1,746
Income tax (expense) benefit	(134)	(372)
Net Unrealized Gains (Losses), Net of Tax Included in Accumulated Other Comprehensive Income (Loss)	489	1,374
Gross Unrealized Losses
Total unrealized gains (losses) on available-for-sale debt securities	(88,411)	(83,751)
Income tax (expense) benefit	19,041	17,824
Net Unrealized Gains (Losses), Net of Tax Included in Accumulated Other Comprehensive Income (Loss)	(69,370)	(65,927)
Net Unrealized Losses
Total unrealized gains (losses) on available-for-sale debt securities	(87,788)	(82,005)
Income tax (expense) benefit	18,907	17,452
Net Unrealized Gains (Losses), Net of Tax Included in Accumulated Other Comprehensive Income (Loss)	$ (68,881)	$ (64,553)