Acquisitions and Sale of Businesses - Allocation of the purchase price of subsidiary (Details) - USD ($) $ in Millions		12 Months Ended
	Dec. 06, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisitions [Line Items]
Payments to acquire subsidiaries		$ 123	$ 3	$ 0
Verikai, Inc.
Business Acquisitions [Line Items]
Payments to acquire subsidiaries	$ 120
Contingent consideration	23
Total purchase price	143
Tangible assets acquired	16
Liabilities acquired	3
Net tangible assets acquired, at fair value	13
Excess purchase price over net tangible assets acquired	130
Intangible assets acquired	76
Deferred tax on intangible assets acquired	16
Goodwill acquired during period	$ 70	$ 70