Fair Value Measurements (Details Narrative) $ in Thousands	9 Months Ended
Sep. 30, 2018 USD ($) integer	Dec. 31, 2017 USD ($)
Number of corporate bonds \| integer	78
Unrealized loss on corporate bonds	$ 567
Amortized cost of investments	191,853
Carrying amount of other long-term debt	88,755	$ 118,317
Fair value of other long-term debt	85,642	$ 122,271
Fair Value, Measurements, Recurring [Member]
Assets measured at fair value	$ 191,288

No definition available.

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

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- Definition

Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

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- Definition

Amount before tax and reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

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