Organization and Description of the Business (Details) $ / shares in Units, $ in Millions		3 Months Ended	9 Months Ended
	Mar. 25, 2017	Sep. 30, 2019 USD ($) $ / shares shares	Sep. 30, 2019 USD ($) segment $ / shares shares	Feb. 25, 2019
Business Acquisition [Line Items]
Number of reportable segments (in segments) | segment			3
Ordinary shares repurchased (in shares) | shares		2,787,247	16,588,838
Average price of ordinary shares repurchased (in dollars per share) | $ / shares		$ 9.10	$ 12.54
Value of treasury stock acquired using the cost method | $		$ 25.4	$ 208.3
Parent Company
Business Acquisition [Line Items]
Percent of interest sold	24.95%
BrightSphere Investment Group | Paulson
Business Acquisition [Line Items]
Parent owned interest				21.70%