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Note 6 - Fair Value Measurements - Change in Fair Value Measurement Impacts Net Income (Details) - Valuation, Market Approach [Member] | Jun. 30, 2021 | Dec. 31, 2020
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Pull-through Rate [Member] | Minimum [Member] | Interest Rate Contract [Member] |  |
Derivative asset (liability) | 0.7190 |
Pull-through Rate [Member] | Minimum [Member] | Forward Contract [Member] |  |
Derivative asset (liability) | 0.7190 |
Pull-through Rate [Member] | Maximum [Member] | Interest Rate Contract [Member] |  |
Derivative asset (liability) | 0.8500 |
Pull-through Rate [Member] | Maximum [Member] | Forward Contract [Member] |  |
Derivative asset (liability) | 0.8500 |
Pull-through Rate [Member] | Weighted Average [Member] | Interest Rate Contract [Member] |  |
Derivative asset (liability) | 0.7860 |
Pull-through Rate [Member] | Weighted Average [Member] | Forward Contract [Member] |  |
Derivative asset (liability) | 0.7860 |
Current Reference Price [Member] | Minimum [Member] | Interest Rate Contract [Member] |  |
Derivative asset (liability) | 0.0101 | 1.0191
Current Reference Price [Member] | Minimum [Member] | Forward Contract [Member] |  |
Derivative asset (liability) | 0.0101 | 1.0191
Current Reference Price [Member] | Maximum [Member] | Interest Rate Contract [Member] |  |
Derivative asset (liability) | 0.0103 | 1.0302
Current Reference Price [Member] | Maximum [Member] | Forward Contract [Member] |  |
Derivative asset (liability) | 0.0103 | 1.0319

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- Definition Value of input used to measure net derivative asset (liability). + 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 (bbb)(2) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
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