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Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017
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Fair Value Disclosures [Abstract] |  |
Life insurance contracts and cost-method investments | $ 515 | $ 311

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- Definition Life insurance contracts and cost method investments fair value disclosure + References No definition available. + Details
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- References No definition available. + Details
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