Other Policyholder Funds and Benefits Payable (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Other policyholder funds and benefits payable	$ 645	$ 659	$ 658
Universal Life
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Other policyholder funds and benefits payable	226	236	$ 232	$ 253
Policyholder Account Balance, Premium Received	10	11
Policyholder Account Balance, Policy Charge	15	18
Policyholder Account Balance, Surrender and Withdrawal	4	3
Policyholder Account Balance, Benefit Payment	4	16
Policyholder Account Balance, Interest Expense	$ 7	$ 9
Policyholder Account Balance, Weighted Average Crediting Rate	4.20%	4.20%
Policyholder Account Balance, Net Amount at Risk	$ 928	$ 1,010
Policyholder Account Balance, Cash Surrender Value	$ 224	233
Universal Life | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 to 0499 | Minimum
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Policyholder Account Balance, Guaranteed Minimum Credit Rating	4.00%
Universal Life | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 to 0499 | Maximum
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Policyholder Account Balance, Guaranteed Minimum Credit Rating	5.00%
Universal Life | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 to 0499 | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Other policyholder funds and benefits payable	$ 225	234
Short-Duration Insurance, Other
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Other policyholder funds and benefits payable	$ 419	$ 423