Goodwill - Goodwill by Segment (Details) - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022
Goodwill [Line Items]
Goodwill	$ 59.3	$ 58.2
Commercial
Goodwill [Line Items]
Goodwill	33.7	32.6
Institutional
Goodwill [Line Items]
Goodwill	9.8	9.8
Retail
Goodwill [Line Items]
Goodwill	5.8	5.8
Global Payments
Goodwill [Line Items]
Goodwill	$ 10.0	$ 10.0