Schedule V (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Allowance for premiums and insurances balances receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, Beginning of year	$ 169	$ 185	$ 205
Charged to Costs and Expenses	(7)	0	(15)
Write Offs	(29)	(15)	(2)
Reclassified to Assets Held for Sale	0	0	0
Other Changes	6	(1)	(3)
Balance, End of year	139	169	185
Federal and foreign valuation allowance for deferred tax assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, Beginning of year	4,246	1,987	1,330
Charged to Costs and Expenses	(357)	(25)	718
Write Offs	0	0	0
Reclassified to Assets Held for Sale	(82)	0	0
Other Changes	(691)	2,284	(61)
Balance, End of year	$ 3,116	$ 4,246	$ 1,987