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Note 6 - Fair Value Measurements - Fair Value Assets by Investment Category (Details) - USD ($) $ in Thousands | Dec. 31, 2024 | Dec. 31, 2023
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Cash and Cash Equivalents [Member] |  |
Assets, fair value | $ 68,253 | $ 89,371
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 1 | 31,188
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 1,335 | 639
Other Current Assets [Member] |  |
Assets, fair value | 2,168 | 3,293
Other Current Assets [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 566 | 303
Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 1,602 | 2,990
Cash [Member] | Cash and Cash Equivalents [Member] |  |
Assets, fair value | 66,917 | 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 | 1 | 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 | 566 | 303
Certificates of Deposit [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 1,335 | 639
Certificates of Deposit [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 1,602 | 2,990
Reported Value Measurement [Member] |  |
Assets, fair value | 70,422 | 92,664
Reported Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 567 | 31,491
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 2,938 | 3,629
Reported Value Measurement [Member] | Cash [Member] |  |
Assets, fair value | 66,917 | 57,544
Reported Value Measurement [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 1 | 31,188
Reported Value Measurement [Member] | Money Market Funds, Rabbi Trust [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 566 | 303
Reported Value Measurement [Member] | Certificates of Deposit [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 2,938 | 3,629
Estimate of Fair Value Measurement [Member] |  |
Assets, fair value | 70,832 | 92,961
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 567 | 31,491
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | 3,348 | 3,926
Estimate of Fair Value Measurement [Member] | Cash [Member] |  |
Assets, fair value | 66,917 | 57,544
Estimate of Fair Value Measurement [Member] | Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 1 | 31,188
Estimate of Fair Value Measurement [Member] | Money Market Funds, Rabbi Trust [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Assets, fair value | 566 | 303
Estimate of Fair Value Measurement [Member] | Certificates of Deposit [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Assets, fair value | $ 3,348 | $ 3,926

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