Asset Management Fees - Asset Management Fees (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Asset management fees	$ 24	$ 23
CLOs
Disaggregation of Revenue [Line Items]
Asset management fees	11	4
Opportunity funds and liquid strategies
Disaggregation of Revenue [Line Items]
Asset management fees	4	2
Wind-down funds
Disaggregation of Revenue [Line Items]
Asset management fees	3	9
Asset management fees
Disaggregation of Revenue [Line Items]
Asset management fees	18	15
Performance fees
Disaggregation of Revenue [Line Items]
Asset management fees	1	0
Reimbursable fund expenses
Disaggregation of Revenue [Line Items]
Asset management fees	5	8
CLO's, Before Rebates
Disaggregation of Revenue [Line Items]
Asset management fees	$ 14	$ 10