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Note 1 - Summary of Significant Accounting Policies - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands | Sep. 30, 2020 | Dec. 31, 2019
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Fair Value, Inputs, Level 1 [Member] |  |
Total Assets | $ 3,247 | $ 3,949
Fair Value, Inputs, Level 1 [Member] | Equity Funds [Member] |  |
Investments | 1,665 | 1,586
Fair Value, Inputs, Level 1 [Member] | Money Market and Mutual Funds [Member] |  |
Other Assets | 1,582 | 2,363
Fair Value, Inputs, Level 2 [Member] |  |
Total Assets | 9,018 | 8,184
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member] |  |
Investments | 2,887 | 2,124
Fair Value, Inputs, Level 2 [Member] | Government-backed and Government-sponsored Enterprises' Debt Securities [Member] |  |
Investments | $ 6,131 | $ 6,060

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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 Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -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 + Details
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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 + Details
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- Definition Fair value portion of other assets. + References No definition available. + Details
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