Legal Proceedings (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Jun. 30, 2025
Loss Contingencies [Line Items]
Possible aggregate loss		$ 100.0
Customer Arbitration Against the Company's Brokerage Subsidiary	$ 132.5
Compensatory Damages [Member]
Loss Contingencies [Line Items]
Customer Arbitration Against the Company's Brokerage Subsidiary	26.5
Punitive Damages [Member]
Loss Contingencies [Line Items]
Customer Arbitration Against the Company's Brokerage Subsidiary	79.5
Attorneys' Fees and Costs [Member]
Loss Contingencies [Line Items]
Customer Arbitration Against the Company's Brokerage Subsidiary	$ 26.5