Acquisitions and Sale of Businesses - Allocation of the purchase price of subsidiary 2 (Details) - USD ($) $ in Millions		12 Months Ended
	Dec. 06, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Business Acquisitions [Line Items]
Cash paid at purchase		$ 234	$ 10	$ 123
Verikai, Inc.
Business Acquisitions [Line Items]
Cash paid at purchase	$ 120
Contingent consideration — acquisitions	23
Total purchase price	143
Total tangible assets acquired	16
Total liabilities acquired	3
Net tangible assets acquired, at fair value	13
Excess purchase price over net tangible assets acquired	130
Deferred tax on intangible assets acquired	16
Goodwill acquired during period	$ 70			$ 70