Business Segment Information - Net Revenues Derived From Investment Management, Research and Related Services (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Revenues:
Total revenues	$ 1,098,124	$ 1,127,868
Less: Broker-dealer related Interest expense	17,517	23,717
Net revenues	1,080,607	1,104,151
Reportable Segment
Revenues:
Total revenues	1,098,124	1,127,868
Less: Broker-dealer related Interest expense	17,517	23,717
Net revenues	1,080,607	1,104,151
Institutions | Reportable Segment
Revenues:
Total revenues	172,005	157,273
Retail | Reportable Segment
Revenues:
Total revenues	599,972	536,177
Private Wealth Management | Reportable Segment
Revenues:
Total revenues	298,797	278,308
Bernstein Research Services | Reportable Segment
Revenues:
Total revenues	0	96,222
Other | Reportable Segment
Revenues:
Total revenues	$ 27,350	$ 59,888