Other Real Estate Owned (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Repossessed Assets [Abstract]
Balance at beginning of year	$ 6.7	$ 14.4	$ 16.5	$ 12.7
Additions	0.9	0.0	4.6	2.5
Write-down of OREO	0.0	(0.3)	(4.2)	(1.1)
Dispositions	(3.2)	(2.5)	(12.5)	(2.5)
Balance at end of year	$ 4.4	$ 11.6	$ 4.4	$ 11.6