Note 1 - Significant Accounting Policies - Changes to the Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Allowance for doubtful accounts | $ 9,692 | $ 9,114 | $ 7,602 |
| Additional provisions for the year | 206 | 1,233 | 1,512 |
| Uncollectible accounts written off | (655) | ||
| Allowance for doubtful accounts | $ 9,898 | $ 9,692 | $ 9,114 |
| X | ||||||||||
- Definition Amount of allowance for credit loss on accounts receivable. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of direct write-downs of accounts receivable charged against the allowance. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of expense (reversal of expense) for expected credit loss on accounts receivable. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|