Revenue from Contracts with Clients (Client Receivables) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Total Client Receivables	$ 996.8	$ 928.4
Trust Fees Receivable, net
Disaggregation of Revenue [Line Items]
Total Client Receivables	932.3	863.5
Contract with customer, asset, allowance for credit loss	12.0	15.9
Other
Disaggregation of Revenue [Line Items]
Total Client Receivables	$ 64.5	$ 64.9