Deferred Policy Acquisition Costs - Rollforward of LDTI and DSI Adoption Adjustments (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021	Dec. 31, 2020
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost	$ 11,999	$ 12,857	$ 12,961	$ 13,001
Deferred sale inducement cost					$ 679
As Previously Reported
Summary of Significant Accounting Policies [Line Items]
Deferred sale inducement cost					281
Effect of Change
Summary of Significant Accounting Policies [Line Items]
Deferred sale inducement cost					398
Individual Retirement
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost	4,694	4,597	4,593	4,553
Deferred sale inducement cost					474
Individual Retirement | As Previously Reported
Summary of Significant Accounting Policies [Line Items]
Deferred sale inducement cost					190
Individual Retirement | Effect of Change
Summary of Significant Accounting Policies [Line Items]
Deferred sale inducement cost					284
Group Retirement
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost	1,053	1,060	1,063	1,078
Deferred sale inducement cost					205
Group Retirement | As Previously Reported
Summary of Significant Accounting Policies [Line Items]
Deferred sale inducement cost					91
Group Retirement | Effect of Change
Summary of Significant Accounting Policies [Line Items]
Deferred sale inducement cost					114
Life Insurance
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost	4,148	4,839	4,781	4,904
General Insurance
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost	$ 2,037	$ 2,310	$ 2,478	$ 2,428
Long-Duration Insurance Contracts
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					10,466
Long-Duration Insurance Contracts | As Previously Reported
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					7,316
Long-Duration Insurance Contracts | Effect of Change
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					3,150
Long-Duration Insurance Contracts | Individual Retirement
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					4,421
Long-Duration Insurance Contracts | Individual Retirement | As Previously Reported
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					2,359
Long-Duration Insurance Contracts | Individual Retirement | Effect of Change
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					2,062
Long-Duration Insurance Contracts | Group Retirement
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					1,094
Long-Duration Insurance Contracts | Group Retirement | As Previously Reported
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					560
Long-Duration Insurance Contracts | Group Retirement | Effect of Change
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					534
Long-Duration Insurance Contracts | Life Insurance
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					4,918
Long-Duration Insurance Contracts | Life Insurance | As Previously Reported
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					4,371
Long-Duration Insurance Contracts | Life Insurance | Effect of Change
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					547
Long-Duration Insurance Contracts | Institutional Markets
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					33
Long-Duration Insurance Contracts | Institutional Markets | As Previously Reported
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					26
Long-Duration Insurance Contracts | Institutional Markets | Effect of Change
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					7
Long-Duration Insurance Contracts | General Insurance
Summary of Significant Accounting Policies [Line Items]
Deferred acquisition cost					$ 2,500