Goodwill and Other Intangible Assets (Details) - Other Intangible Assets - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	$ 304	$ 306
Intangible assets subject to amortization, accumulated amortization	200	187
Intangible assets subject to amortization, net	104	119
Intangible assets not subject to amortization	226	226
Total other intangible assets, gross carrying amount	530	532
Total other intangible assets, net	330	345
Amortization expense of intangible assets	15	17	$ 13
Estimated intangible asset amortization expense, 2020	15
Estimated intangible asset amortization expense, 2021	14
Estimated intangible asset amortization expense, 2022	13
Estimated intangible asset amortization expense, 2023	12
Estimated intangible asset amortization expense, 2024	12
Customer-related [Member]
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	99	98
Intangible assets subject to amortization, accumulated amortization	21	12
Intangible assets subject to amortization, net	78	86
Contract-based [Member]
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	205	208
Intangible assets subject to amortization, accumulated amortization	179	175
Intangible assets subject to amortization, net	26	$ 33
Insurance Contracts Acquired in Business Combination [Member]
Other intangible assets by major asset class
Estimated intangible asset amortization expense, 2020	5
Estimated intangible asset amortization expense, 2021	4
Estimated intangible asset amortization expense, 2022	3
Estimated intangible asset amortization expense, 2023	3
Estimated intangible asset amortization expense, 2024	$ 2