Goodwill and Other Intangible Assets (Details) - Other Intangible Assets - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	$ 304	$ 300
Intangible assets subject to amortization, accumulated amortization	253	239
Intangible assets subject to amortization, net	51	61
Intangible assets not subject to amortization	226	226
Total other intangible assets, gross carrying amount	530	526
Total other intangible assets, net	277	287
Amortization expense of intangible assets	12	13	$ 14
Estimated intangible asset amortization expense, 2024	12
Estimated intangible asset amortization expense, 2025	11
Estimated intangible asset amortization expense, 2026	11
Estimated intangible asset amortization expense, 2027	8
Estimated intangible asset amortization expense, 2028	2
Customer-related [Member]
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	100	96
Intangible assets subject to amortization, accumulated amortization	59	48
Intangible assets subject to amortization, net	41	48
Contract-based [Member]
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	204	204
Intangible assets subject to amortization, accumulated amortization	194	191
Intangible assets subject to amortization, net	10	$ 13
Insurance Contracts Acquired in Business Combination [Member]
Other intangible assets by major asset class
Estimated intangible asset amortization expense, 2024	2
Estimated intangible asset amortization expense, 2025	2
Estimated intangible asset amortization expense, 2026	1
Estimated intangible asset amortization expense, 2027	1
Estimated intangible asset amortization expense, 2028	$ 1