Goodwill and Intangible Assets (Schedule of Goodwill) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 115,599
Foreign currency translation adjustments	3
Goodwill, ending balance	115,602
Institutional Investors
Goodwill [Roll Forward]
Goodwill, beginning balance	47,108
Foreign currency translation adjustments	0
Goodwill, ending balance	47,108
Investment Managers
Goodwill [Roll Forward]
Goodwill, beginning balance	56,992
Foreign currency translation adjustments	3
Goodwill, ending balance	56,995
Investments In New Businesses
Goodwill [Roll Forward]
Goodwill, beginning balance	11,499
Foreign currency translation adjustments	0
Goodwill, ending balance	$ 11,499