Note 11 - Subsequent Event	6 Months Ended
Jun. 30, 2022
Notes to Financial Statements
Subsequent Events [Text Block]	11. Subsequent Event Nasdaq Compliance On August 9, 2022, the Company received written notice from Nasdaq, indicating that, based upon the closing bid price of the Company’s common stock for the 30 consecutive business day period between June 27, 2022, through August 8, 2022, the Company did not meet the minimum bid price of $1.00 per share required for continued listing on the Nasdaq Global Select Market pursuant to Nasdaq Listing Rule 5550(a)(2). The letter also indicated that the Company will be provided with a compliance period of 180 calendar days, or until February 6, 2023 (the “Compliance Period”), in which to regain compliance pursuant to Nasdaq Listing Rule 5810(c)(3)(A). In order to regain compliance with Nasdaq’s minimum bid price requirement, the Company’s common stock must maintain a minimum closing bid price of $1.00 for at least ten consecutive business days during the Compliance Period. In the event the Company does not regain compliance by the end of the Compliance Period, the Company may be eligible for additional time to regain compliance. To qualify, the Company will be required to meet the continued listing requirement for the market value of its publicly held shares and all other initial listing standards for the Nasdaq Global Select Market, with the exception of the bid price requirement, and will need to provide written notice of its intention to cure the deficiency during the second compliance period. If the Company meets these requirements, the Company may be granted an additional 180 calendar days to regain compliance. However, if it appears to Nasdaq that the Company will be unable to cure the deficiency, or if the Company is not otherwise eligible for the additional cure period, Nasdaq will provide notice that the Company’s common stock will be subject to delisting. The letter has no immediate impact on the listing of the Company’s common stock, which will continue to be listed and traded on the Nasdaq Global Select Market, subject to the Company’s compliance with the other listing requirements of the Nasdaq Global Select Market. Although the Company will use all reasonable efforts to achieve compliance with Rule 5550(a)(2), there can be no assurance that the Company will be able to regain compliance with that rule or will otherwise be in compliance with other listing criteria of the Nasdaq Global Select Market.

Note 11 - Subsequent Event

6 Months Ended

Jun. 30, 2022

11. Subsequent Event

Nasdaq Compliance

On August 9, 2022, the Company received written notice from Nasdaq, indicating that, based upon the closing bid price of the Company’s common stock for the 30 consecutive business day period between June 27, 2022, through August 8, 2022, the Company did not meet the minimum bid price of $1.00 per share required for continued listing on the Nasdaq Global Select Market pursuant to Nasdaq Listing Rule 5550(a)(2). The letter also indicated that the Company will be provided with a compliance period of 180 calendar days, or until February 6, 2023 (the “Compliance Period”), in which to regain compliance pursuant to Nasdaq Listing Rule 5810(c)(3)(A).

In order to regain compliance with Nasdaq’s minimum bid price requirement, the Company’s common stock must maintain a minimum closing bid price of $1.00 for at least ten consecutive business days during the Compliance Period. In the event the Company does not regain compliance by the end of the Compliance Period, the Company may be eligible for additional time to regain compliance. To qualify, the Company will be required to meet the continued listing requirement for the market value of its publicly held shares and all other initial listing standards for the Nasdaq Global Select Market, with the exception of the bid price requirement, and will need to provide written notice of its intention to cure the deficiency during the second compliance period. If the Company meets these requirements, the Company may be granted an additional 180 calendar days to regain compliance. However, if it appears to Nasdaq that the Company will be unable to cure the deficiency, or if the Company is not otherwise eligible for the additional cure period, Nasdaq will provide notice that the Company’s common stock will be subject to delisting.

The letter has no immediate impact on the listing of the Company’s common stock, which will continue to be listed and traded on the Nasdaq Global Select Market, subject to the Company’s compliance with the other listing requirements of the Nasdaq Global Select Market. Although the Company will use all reasonable efforts to achieve compliance with Rule 5550(a)(2), there can be no assurance that the Company will be able to regain compliance with that rule or will otherwise be in compliance with other listing criteria of the Nasdaq Global Select Market.