Fair Value Measurements - Reconciliation of Level 3 Investments Securities (Details) - Debt Securities [Member] - USD ($) $ in Millions |
12 Months Ended | |
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Dec. 31, 2018 |
Dec. 31, 2017 |
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| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||
| Balance, beginning of period | $ 151 | $ 58 |
| Purchases of investments | 25 | 78 |
| Payments on investments | (5) | (3) |
| Transfers to investments | 0 | 17 |
| Unrealized gains (losses) on investments recorded in OCI | (1) | 1 |
| Balance, end of period | $ 170 | $ 151 |
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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- Definition Amount of gain (loss) recognized in other comprehensive income (loss) for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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