Note 5 - Concentration of Credit Risk	12 Months Ended
Dec. 31, 2020
Notes to Financial Statements
Concentration Risk Disclosure [Text Block]	5. Concentration of Credit Risk: Financial instruments that potentially expose us to credit risk consist primarily of cash and cash equivalents as well as accounts receivable, net which are generally not collateralized. We maintain our cash and cash equivalents in higher credit quality financial institutions in order to limit the amount of credit exposure. The total domestic cash balances are insured by the Federal Deposit Insurance Corporation (“FDIC”) to a maximum amount of $250.0 thousand per bank as of December 31, 2020 and 2019. As of December 31, 2020 and 2019, we had cash balances on deposit with eleven and ten banks that exceeded the balance insured by the FDIC limit by approximately $92.8 million and $36.4 million, respectively. As of December 31, 2020 and 2019, we also had cash on deposit with foreign banks of approximately $122.5 million and $145.7 million, respectively. We consider the concentration of credit risk associated with our accounts receivable to be commercially reasonable and believe that such concentration does not result in the significant risk of near-term severe adverse impacts. Our top fifty customers represent approximately 33% of revenues for 2020 and 2019, and 34% for 2018, with no individual customer accounting for more than approximately 3% of revenues for the years ended December 31, 2020, 2019, and 2018. No individual customer comprised more than approximately 2% and 3% of accounts receivable as of December 31, 2020 and 2019, respectively.

Note 5 - Concentration of Credit Risk

12 Months Ended

Dec. 31, 2020

Concentration Risk Disclosure [Text Block]

Financial instruments that potentially expose us to credit risk consist primarily of cash and cash equivalents as well as accounts receivable, net which are generally not collateralized. We maintain our cash and cash equivalents in higher credit quality financial institutions in order to limit the amount of credit exposure. The total domestic cash balances are insured by the Federal Deposit Insurance Corporation (“FDIC”) to a maximum amount of $250.0 thousand per bank as of December 31, 2020 and 2019. As of December 31, 2020 and 2019, we had cash balances on deposit with eleven and ten banks that exceeded the balance insured by the FDIC limit by approximately $92.8 million and $36.4 million, respectively. As of December 31, 2020 and 2019, we also had cash on deposit with foreign banks of approximately $122.5 million and $145.7 million, respectively.

We consider the concentration of credit risk associated with our accounts receivable to be commercially reasonable and believe that such concentration does not result in the significant risk of near-term severe adverse impacts. Our top fifty customers represent approximately 33% of revenues for 2020 and 2019, and 34% for 2018, with no individual customer accounting for more than approximately 3% of revenues for the years ended December 31, 2020, 2019, and 2018. No individual customer comprised more than approximately 2% and 3% of accounts receivable as of December 31, 2020 and 2019, respectively.