Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Disaggregation of Revenue [Line Items]
Revenues	$ 216,385	$ 227,029	$ 644,842	$ 673,455
Investment management fees
Disaggregation of Revenue [Line Items]
Revenues	183,762	193,843	549,329	573,855
Open-end funds
Disaggregation of Revenue [Line Items]
Revenues	73,270	79,428	217,686	237,991
Closed-end funds
Disaggregation of Revenue [Line Items]
Revenues	15,635	14,942	45,369	43,741
Retail separate accounts
Disaggregation of Revenue [Line Items]
Revenues	52,172	52,068	158,262	153,265
Institutional accounts
Disaggregation of Revenue [Line Items]
Revenues	$ 42,685	$ 47,405	$ 128,012	$ 138,858