Segment Information - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) segment	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2
Total revenue	$ 17,181	$ 15,698	$ 13,376
Eliminations
Segment Reporting Information [Line Items]
Total revenue	(16)	(28)	(12)
Eliminations | Risk Capital
Segment Reporting Information [Line Items]
Total revenue	11	16	6
Eliminations | Human Capital
Segment Reporting Information [Line Items]
Total revenue	$ 5	$ 12	$ 6