Goodwill and Core Deposit Intangibles - Goodwill Narrative (Details) - USD ($) $ in Millions			12 Months Ended
	Jul. 01, 2025	Jul. 01, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Goodwill [Line Items]
Impairment of goodwill	$ 0.0	$ 0.0
Reductions due to sale of health savings accounts			$ 13.6	$ 14.6	$ 15.7