Non-U.S. Activities - Narrative (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segment Reporting Information [Line Items]
Total assets	$ 338,481		$ 338,481		$ 297,258
Non-U.S.
Segment Reporting Information [Line Items]
Management fees, percent	0.24	0.25	0.25	0.26
Service fees, percent	0.47	0.47	0.47	0.46
Total assets	$ 95,260	$ 80,750	$ 95,260	$ 80,750