Financial Instruments (Details) - USD ($) $ in Billions |
Mar. 31, 2019 |
Dec. 31, 2018 |
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| Recurring | Level 2 market data | ||
| Financial Instruments | ||
| Fair value of senior notes | $ 3.5 | $ 3.9 |
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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. No definition available.
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- Definition Fair value portion of notes payable. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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