Regulatory Requirements and Subsidiary Dividend Restrictions - Customer Reserve Requirements (Details) - USD ($) $ in Millions	Oct. 04, 2022	Sep. 30, 2022
Capital and Other Regulatory Requirements [Line Items]
Cash reserve deposit required		$ 1.6
Customer SRBA
Capital and Other Regulatory Requirements [Line Items]
Cash reserve deposit required		3.5
Customer SRBA | Subsequent Event
Capital and Other Regulatory Requirements [Line Items]
Cash reserve deposit made	$ 3.9
PAB
Capital and Other Regulatory Requirements [Line Items]
Cash reserve deposit required		10.3
PAB Reserve Requirement
Capital and Other Regulatory Requirements [Line Items]
Cash reserve deposit required		10.3
PAB SRBA
Capital and Other Regulatory Requirements [Line Items]
Cash reserve deposit required		$ 12.9
PAB SRBA | Subsequent Event
Capital and Other Regulatory Requirements [Line Items]
Cash reserve withdrawal	$ 1.1