Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accounting Policies [Abstract]
Realized losses marketable securities	$ (86)	$ (174)	$ 361	$ 303
Unrealized gains (losses) in marketable securities	3	124	(14)	262
Dividend income	44	18	121	72
Total	$ (39)	$ (32)	$ (254)	$ 31

The representation of realized gain or loss, unrealized gain or loss, and dividend income related to marketable securities.

No definition available.

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- References

No definition available.

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- Definition

Amount of operating dividend income on securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.2)
-URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260

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- Definition

Amount of realized gain (loss) on investment in marketable security, including other-than-temporary impairment (OTTI).

+ References

No definition available.

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- Definition

Amount of unrealized gain (loss) on investment in marketable security.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

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