Value of Business Acquired, Goodwill, and Other Intangible Assets (Estimated Amortization Expense Over Next Five Years) (Details) $ in Millions	Sep. 30, 2023 USD ($)
Finite-Lived Intangible Assets [Line Items]
Fourth quarter of 2023, VOBA	$ 67
Fourth quarter of 2023, Other intangible assets	103
2024, Other intangible assets	354
2025, Other intangible assets	314
2026, Other intangible assets	288
2027, Other intangible assets	265
2028, Other intangible assets	253
Total, other intangible assets	1,577
2024, Other intangible assets	270
2025, Other intangible assets	202
2026, Other intangible assets	181
2027, Other intangible assets	165
Present Value of Future Insurance Profits, Expected Amortization, Total	1,115
2024, Other intangible assets	230
Huatai Group | Unearned Premium Reserves Intangible Asset
Finite-Lived Intangible Assets [Line Items]
Fourth quarter of 2023, Other intangible assets	16	[1]
2024, Other intangible assets	30	[1]
2025, Other intangible assets	16	[1]
2026, Other intangible assets	7	[1]
2027, Other intangible assets	3	[1]
2028, Other intangible assets	0	[1]
Total, other intangible assets	72	[1]
Huatai Group | Use Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Fourth quarter of 2023, Other intangible assets	3	[2]
2024, Other intangible assets	12	[2]
2025, Other intangible assets	12	[2]
2026, Other intangible assets	12	[2]
2027, Other intangible assets	13	[2]
2028, Other intangible assets	13	[2]
Total, other intangible assets	65	[2]
Chubb Acquired Purchased Intangible assets
Finite-Lived Intangible Assets [Line Items]
Fourth quarter of 2023, Other intangible assets	84
2024, Other intangible assets	312
2025, Other intangible assets	286
2026, Other intangible assets	269
2027, Other intangible assets	249
2028, Other intangible assets	240
Total, other intangible assets	$ 1,440

[1] Recognized in Policy acquisition costs in the Consolidated statements of operations.

[2] Recognized in Other (income) expense in the Consolidated statements of operations