Acquisitions (Narrative) (Details) - USD ($) $ in Thousands	Aug. 01, 2024	Aug. 01, 2023	Mar. 01, 2023	Dec. 31, 2024	Dec. 31, 2023
Business Acquisition [Line Items]
Goodwill				$ 1,395,218	$ 1,388,243
Institutional Group [Member]
Business Acquisition [Line Items]
Goodwill				$ 1,060,209	$ 1,053,234
CB Resource and Finance 500 [Member]
Business Acquisition [Line Items]
Date of acquisition	Aug. 01, 2024
Payments to Acquire Intangible Assets	$ 4,500
CB Resource and Finance 500 [Member] | Institutional Group [Member]
Business Acquisition [Line Items]
Goodwill	$ 6,800
Sierra Pacific Securities, LLC [Member]
Business Acquisition [Line Items]
Date of acquisition		Aug. 01, 2023
Payments to Acquire Intangible Assets		$ 18,100
Sierra Pacific Securities, LLC [Member] | Institutional Group [Member]
Business Acquisition [Line Items]
Goodwill		$ 6,800
Torreya Partners, LLC [Member]
Business Acquisition [Line Items]
Date of acquisition			Mar. 01, 2023
Payments to Acquire Intangible Assets			$ 5,300
Torreya Partners, LLC [Member] | Institutional Group [Member]
Business Acquisition [Line Items]
Goodwill			$ 55,100