Investments (Investments in Marketable Equity Securities) (Details 1) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Investments [Abstract]
Total Cost	$ 282,349	$ 282,563
Gross unrealized gains	253,215	216,111
Gross unrealized losses	0	(2,284)
Total Fair Value	$ 535,564	$ 496,390

Amount of unrealized gain on investment on equity security measured at fair value with change in fair value recognized in net income (FV-NI).

No definition available.

+ Details

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- Definition

Amount of unrealized loss on investment on equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740

+ Details

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- Definition

Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value.

+ References

No definition available.

+ Details

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- References

No definition available.

+ Details

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