Asset Management Fees - Asset Management Fees (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Asset management fees	$ 0	$ 16	$ 53	$ 71
Management fees
Disaggregation of Revenue [Line Items]
Asset management fees	0	11	21	41
Performance fees
Disaggregation of Revenue [Line Items]
Asset management fees	0	2	18	17
Reimbursable fund expenses
Disaggregation of Revenue [Line Items]
Asset management fees	$ 0	$ 3	$ 14	$ 13