Revenue Recognition - Summary of Revenue Recognition (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Schedule Of Revenue Recognition [Line Items]
Gain (losses) on change in fair value of other real estate owned and other assets not within scope of ASC 606	$ 0.1	$ 1.5	$ 0.1	$ (1.0)
Net Swap Fee and Valuation Income [Member]
Schedule Of Revenue Recognition [Line Items]
Gain (losses) on change in fair value of other real estate owned and other assets not within scope of ASC 606	$ 1.4	$ 0.8	$ 0.5	$ 3.4