Business Dispositions - Carrying Value of Assets and Liabilities to be Transferred in Sale (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 0	$ 177
Disposal Group, Including Discontinued Operation, Liabilities, Total	0	158
Continental Europe Operations [Member] | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents	150	142
Disposal Group, Including Discontinued Operation, Other Assets	13	35
Assets held for sale	163	177
Net change in reserves transferred to liabilities held for sale	81	84
Disposal Group, Including Discontinued Operation, Deferred Revenue	19	31
Disposal Group, Including Discontinued Operation, Other Liabilities	52	43
Disposal Group, Including Discontinued Operation, Liabilities, Total	152	158
Disposal Group, Including Discontinued Operation, Consideration	$ 11	14
Continental Europe Operations [Member] | Fair Value, Recurring [Member] | Fixed Maturities and Short-Term Investments [Member] | Securities available-for-sale and other | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets Held-for-sale, Long Lived, Fair Value Disclosure		84
Continental Europe Operations [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Recurring [Member] | Fixed Maturities and Short-Term Investments [Member] | Securities available-for-sale and other | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets Held-for-sale, Long Lived, Fair Value Disclosure		1
Continental Europe Operations [Member] | Significant Observable Inputs (Level 2) | Fair Value, Recurring [Member] | Fixed Maturities and Short-Term Investments [Member] | Securities available-for-sale and other | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets Held-for-sale, Long Lived, Fair Value Disclosure		83
Continental Europe Operations [Member] | Significant Unobservable Inputs (Level 3) | Fair Value, Nonrecurring [Member] | Fixed Maturities and Short-Term Investments [Member] | Securities available-for-sale and other | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets Held-for-sale, Long Lived, Fair Value Disclosure		$ 70