Segment Information - Narrative (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) segment	Sep. 30, 2024 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segment | segment			2
Total revenue	$ 3,997	$ 3,721	$ 12,881	$ 11,551
Eliminations
Segment Reporting Information [Line Items]
Total revenue	(3)	(3)	(12)	(26)
Eliminations | Risk Capital
Segment Reporting Information [Line Items]
Total revenue	1	1	5	16
Eliminations | Human Capital
Segment Reporting Information [Line Items]
Total revenue	$ 3	$ 3	$ 7	$ 10