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Derivative Financial Instruments - CDS notional amount by credit rating and fair value of protection sold (Details) - USD ($) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2021 | Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract] |  |
Term of credit default swaps (in years) | 5 years |
Derivative [Line Items] |  |
Notional amount | $ 5,312 | $ 5,191
Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 755 | 754
Fair value | 14 | 13
Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 5 | 4
Fair value | 0 | 0
Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 750 | 750
Fair value | 14 | 13
AAA | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 6 | 6
AAA | Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 0 | 0
AAA | Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 6 | 6
AA | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 12 | 12
AA | Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 0 | 0
AA | Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 12 | 12
A | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 150 | 156
A | Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 0 | 0
A | Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 150 | 156
BBB | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 492 | 492
BBB | Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 0 | 0
BBB | Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 492 | 492
BB and lower | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 95 | 88
BB and lower | Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 5 | 4
BB and lower | Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | $ 90 | $ 84

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- Definition Term of the credit risk derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4K -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5708775-113959 + Details
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- Definition Fair value of credit risk derivative asset after deduction of credit risk derivative liability. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4K -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5708775-113959 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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