Insurance Liabilities - Discounting of reserves (Details) - USD ($)	3 Months Ended	9 Months Ended
	Mar. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Discounting of Reserves [Line Items]
U.S. workers' compensation		$ 1,825,000,000	$ 1,829,000,000
Retroactive reinsurance		(879,000,000)	(953,000,000)
Total reserve discount		946,000,000	876,000,000
Fortitude RE
Discounting of Reserves [Line Items]
Total reserve discount		$ 480,000,000	500,000,000
Discount ceded on sale (as a percent)	100.00%	100.00%
United Kingdom
Discounting of Reserves [Line Items]
Total reserve discount		$ 131,000,000	$ 116,000,000