Investments - Credit Loss Expense Incurred (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total intent to sell impairments		$ (4,213)	$ 0	$ 0
Total credit loss benefit (expense)		(25)	(7)	(9)
Gross gains		627	37	660
Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)		(21)	(14)	(11)
Fortitude Re
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Gross gains	$ 295
Corporate bonds
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total intent to sell impairments		(3,805)	0	0
Total credit loss benefit (expense)		(24)	(4)	(8)
Corporate bonds | Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)		(23)	(4)	(10)
State and municipal bonds
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total intent to sell impairments		(214)	0	0
RMBS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total intent to sell impairments		(74)	0	0
Total credit loss benefit (expense)		(1)	(3)	0
RMBS | Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)		1	(6)	0
CMBS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total intent to sell impairments		(60)	0	0
ABS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total intent to sell impairments		(57)	0	0
ABS | Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)		1	(4)	0
Hybrid and redeemable preferred securities
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total intent to sell impairments		(3)	0	0
Hybrid and redeemable preferred securities | Realized Gain (Loss)
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Total credit loss benefit (expense)		$ 0	$ 0	$ (1)