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Note 6 - Fair Value Measurements - Fair Value Assets by Investment Category (Details) - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Cash and Cash Equivalents [Member] |  |
Assets, fair value | $ 71,320 | $ 89,371
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 10,995 | 31,188
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 1,094 | 639
Other Current Assets [Member] |  |
Assets, fair value | 2,584 | 3,293
Other Current Assets [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 179 | 303
Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 2,405 | 2,990
Cash [Member] | Cash and Cash Equivalents [Member] |  |
Assets, fair value | 59,231 | 57,544
Cash [Member] | Other Current Assets [Member] |  |
Assets, fair value | 0 | 0
Money Market Funds [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 10,995 | 31,188
Money Market Funds [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 0 | 0
Money Market Funds, Rabbi Trust [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 0 | 0
Money Market Funds, Rabbi Trust [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 179 | 303
Certificates of Deposit [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 1,094 | 639
Certificates of Deposit [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 2,405 | 2,990
Reported Value Measurement [Member] |  |
Assets, fair value | 73,904 | 92,664
Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 11,174 | 31,491
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 3,499 | 3,629
Reported Value Measurement [Member] | Cash [Member] |  |
Assets, fair value | 59,231 | 57,544
Reported Value Measurement [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 10,995 | 31,188
Reported Value Measurement [Member] | Money Market Funds, Rabbi Trust [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 179 | 303
Reported Value Measurement [Member] | Certificates of Deposit [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 3,499 | 3,629
Estimate of Fair Value Measurement [Member] |  |
Assets, fair value | 74,186 | 92,961
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 11,174 | 31,491
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 3,781 | 3,926
Estimate of Fair Value Measurement [Member] | Cash [Member] |  |
Assets, fair value | 59,231 | 57,544
Estimate of Fair Value Measurement [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 10,995 | 31,188
Estimate of Fair Value Measurement [Member] | Money Market Funds, Rabbi Trust [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 179 | 303
Estimate of Fair Value Measurement [Member] | Certificates of Deposit [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | $ 3,781 | $ 3,926

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