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Investments Investments - Gross unrealized losses by unrealized loss position and credit quality (Details) - USD ($) $ in Millions | Mar. 31, 2020 | Dec. 31, 2019
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Investment grade fixed income securities |  |
Schedule of Investments [Line Items] |  |
Fixed income securities with unrealized loss position less than 20% of amortized cost, net (1) (2) | $ (579) |
Fixed income securities with unrealized loss position greater than or equal to 20% of amortized cost | (137) |
Total unrealized losses | (716) | $ (61)
Below investment grade fixed income securities |  |
Schedule of Investments [Line Items] |  |
Fixed income securities with unrealized loss position less than 20% of amortized cost, net (1) (2) | (311) |
Fixed income securities with unrealized loss position greater than or equal to 20% of amortized cost | (257) |
Total unrealized losses | (568) | (35)
Unrealized losses having loss of less than twenty percent, less than 12 months | (304) |
Fixed income securities |  |
Schedule of Investments [Line Items] |  |
Fixed income securities with unrealized loss position less than 20% of amortized cost, net (1) (2) | (890) |
Fixed income securities with unrealized loss position greater than or equal to 20% of amortized cost | (394) |
Total unrealized losses | $ (1,284) | $ (96)

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- Definition The amount of unrealized losses that are related to securities with an unrealized loss position less than 20% of cost or amortized cost. + References No definition available. + Details
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- Definition The amount of unrealized losses that are related to securities with an unrealized loss position greater than 20% of cost or amortized cost. + References No definition available. + Details
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- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=118955579&loc=SL82922888-210455 + Details
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