Goodwill and Other Intangible Assets - Changes in Goodwill and Other Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Finite-lived Intangible Assets [Roll Forward]
Other intangible assets, beginning of period	$ 112,645
Amortization	(3,850)	$ (4,096)
Other intangible assets, end of period	108,795		$ 112,645
Core Deposit Premium
Finite-lived Intangible Assets [Roll Forward]
Other intangible assets, beginning of period	101,344	116,016	116,016
Amortization	(3,442)		(14,672)
Other intangible assets, end of period	97,902		101,344
Books of Business Intangible
Finite-lived Intangible Assets [Roll Forward]
Other intangible assets, beginning of period	11,301	$ 12,935	12,935
Amortization	(408)		(1,634)
Other intangible assets, end of period	$ 10,893		$ 11,301