Business Dispositions - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Disposition of Business	$ 51	$ 51
Continental Europe Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Consideration	14	14
Gain (Loss) on Disposition of Business		(51)	$ 0
Disposal Group, Including Discontinued Operation, Deferred Tax Assets	19	19
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax	32
Contingent Consideration Commission payable	12	$ 12
Net realized capital gains | Continental Europe Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Disposition of Business	$ 51