Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	$ 996,007	$ 1,135,853
Not subject to contracts with customers:
Dividend and interest income, net of interest expense	22,658	8,626
Investment gains (losses)	5,264	(39,024)
Other revenues	162	232
Total revenue not from contract with customer	28,084	(30,166)
Net revenues	1,024,091	1,105,687
Base fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	692,327	747,813
Performance-based fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	36,580	75,969
Bernstein research services
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	100,038	117,807
All-in-management fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	68,788	81,221
12b-1 fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	15,155	19,517
Other distribution fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	57,135	67,603
Shareholder servicing fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	20,293	22,414
Other
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	$ 5,691	$ 3,509