Goodwill and Other Intangible Assets (Details) - Other Intangible Assets - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	$ 298		$ 304
Intangible assets subject to amortization, accumulated amortization	202		200
Intangible assets subject to amortization, net	96		104
Intangible assets not subject to amortization	226		226
Total other intangible assets, gross carrying amount	524		530
Total other intangible assets, net	322		330
Amortization expense of intangible assets	4	$ 4
Estimated intangible asset amortization expense, remainder of 2020	10
Estimated intangible asset amortization expense, 2021	13
Estimated intangible asset amortization expense, 2022	12
Estimated intangible asset amortization expense, 2023	12
Estimated intangible asset amortization expense, 2024	11
Customer-related [Member]
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	94		99
Intangible assets subject to amortization, accumulated amortization	22		21
Intangible assets subject to amortization, net	72		78
Contract-based [Member]
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	204		205
Intangible assets subject to amortization, accumulated amortization	180		179
Intangible assets subject to amortization, net	24		$ 26
Insurance Contracts Acquired in Business Combination [Member]
Other intangible assets by major asset class
Estimated intangible asset amortization expense, remainder of 2020	4
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