Subsequent Events	6 Months Ended
	Jun. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsOn July 24, 2020, BrightSphere Inc., a Delaware corporation and wholly owned subsidiary of the Company, entered into a Purchase Agreement (the “CR Purchase Agreement”) with Copper Rock Capital Partners LLC (“Copper Rock”), an Affiliate within the Liquid Alpha segment, and Spouting Rock Asset Management LLC (“Spouting Rock”). Pursuant to the CR Purchase Agreement, Spouting Rock has purchased all of BrightSphere Inc.’s equity interests in Copper Rock. The consummation of the transaction did not have a significant impact on the Condensed Consolidated Financial Statements of the Company.On July 26, 2020, the Company, through its subsidiaries BrightSphere Intermediary (BHMS) LLC (the “Seller”), BHMS Investment GP LLC (“BHMS GP”), BHMS Investment Holdings LP (“BHMS LP”), and Barrow, Hanley, Mewhinney & Strauss, LLC (“Barrow Hanley”), an Affiliate within the Liquid Alpha segment, entered into an Equity Purchase Agreement (the “BHMS Purchase Agreement”) with Perpetual US Holdings Company Inc. (“Perpetual”), pursuant to which Perpetual agreed to purchase all of the Company’s interests in Barrow Hanley in exchange for $319 million of cash consideration, on a cash-free, debt-free basis, subject to certain customary closing and post-closing adjustments. Barrow Hanley comprised $17.5 million of the Company’s net income attributable to controlling interests of $51.5 million for the six months ended June 30, 2020. The transaction is expected to close during fourth quarter of 2020.