Note 4 - Investments - Securities in a Continuous Unrealized Loss Position (Details) $ in Thousands |
Mar. 31, 2023
USD ($)
|
|---|---|
| Fair value unrealized loss, less than 12 months | $ 2,017 |
| Gross unrealized loss, less than 12 months | 43 |
| Fair value unrealized loss, greater than 12 months | 26,282 |
| Gross unrealized loss, greater than 12 months | 1,108 |
| US Treasury Securities [Member] | |
| Fair value unrealized loss, less than 12 months | 0 |
| Gross unrealized loss, less than 12 months | 0 |
| Fair value unrealized loss, greater than 12 months | 15,433 |
| Gross unrealized loss, greater than 12 months | 798 |
| Certificates of Deposit [Member] | |
| Fair value unrealized loss, less than 12 months | 2,017 |
| Gross unrealized loss, less than 12 months | 43 |
| Fair value unrealized loss, greater than 12 months | 10,849 |
| Gross unrealized loss, greater than 12 months | $ 310 |
| X | ||||||||||
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset. Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
|
| X | ||||||||||
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|