Segment Information - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) segment	Jun. 30, 2024 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segment | segment			2
Total revenue	$ 4,155	$ 3,760	$ 8,884	$ 7,830
Eliminations
Segment Reporting Information [Line Items]
Total revenue	(2)	(15)	(9)	(23)
Eliminations | Risk Capital
Segment Reporting Information [Line Items]
Total revenue	1	10	5	16
Eliminations | Human Capital
Segment Reporting Information [Line Items]
Total revenue	$ 2	$ 5	$ 4	$ 7