Note 9 - Cash, Cash Equivalents, Investments and Restricted Cash (Details Textual) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Total	$ 0	$ 0
Redemption, Auction Rate Securities to Date	$ 41,100
Percentage of Auction Rate Securities Redeemed at Par Value	95.00%
Equity Securities without Readily Determinable Fair Value, Amount	$ 5,100	$ 3,300