Fair Value Measurements (Details 1) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and Cash Equivalents, Fair Value Disclosure	$ 126,263	$ 36,112
Available-for-sale Securities, Fair Value Disclosure	26,012	235,547
Investments, Fair Value Disclosure	152,275	271,659
Fair Value, Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and Cash Equivalents, Fair Value Disclosure	126,263	36,112
Available-for-sale Securities, Fair Value Disclosure	0	235,547
Investments, Fair Value Disclosure	126,263	271,659
Fair Value, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Available-for-sale Securities, Fair Value Disclosure	26,012	0
Investments, Fair Value Disclosure	26,012	0
Fair Value, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Available-for-sale Securities, Fair Value Disclosure	0	0
Investments, Fair Value Disclosure	$ 0	$ 0

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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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.

+ References

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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