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General (Details) - USD ($) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2017 | Sep. 30, 2017 | Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |
Available for sale equity securities, included in other comprehensive income |  | $ 966 | $ 509
Limited partnership interests |  | 6,600 | 5,814
Accounting Standards Update 2016-01 |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |
Available for sale equity securities, included in other comprehensive income |  | 966 |
EMA limited partnerships |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |
Limited partnership interests |  | 5,260 | $ 4,530
EMA limited partnerships | Accounting Standards Update 2016-01 |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |
Limited partnership interests |  | $ 200 |
Minimum | Scenario, Forecast | Accounting Standards Update 2016-20 |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |
Deferred policy acquisition costs, period increase | $ 145 |  |
Maximum | Scenario, Forecast | Accounting Standards Update 2016-20 |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |
Deferred policy acquisition costs, period increase | $ 175 |  |

X
- Definition The amount of unrealized gains (losses) included in accumulated other comprehensive income on equity securities which are categorized neither as held-to-maturity nor trading securities, as a result of fair value exceeding (under) its amortized cost, as of the balance sheet date. + References No definition available. + Details
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- Definition Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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