Investments Of Operating Entities And Consolidated Funds - Consolidated Funds - Securities Owned By Enterprise Master (Details) - USD ($) $ in Thousands		Sep. 30, 2020		Dec. 31, 2019
Investment Holdings [Line Items]
Securities owned, at fair value ($254,383 and $941,595 were pledged to various parties)		$ 1,088,566		$ 1,633,552
Other investments		204,610		185,722
Portfolio Funds
Investment Holdings [Line Items]
Other investments		123,787	[1]	114,504
Portfolio Funds | Other Private Investment | Affiliated Entity
Investment Holdings [Line Items]
Other investments	[2],[3]	$ 315		$ 4,448

[1] In accordance with US GAAP, certain investments are measured at fair value using the net asset value per share (or its equivalent) as a practical expedient. Carried interest in portfolio funds have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the condensed consolidated statement of financial condition.

[2] Other private investment represents the Company's closed end investment in a Portfolio Fund that invests in a wireless broadband communication provider in Italy.

[3] These Portfolio Funds are affiliates of the Company.