Note 7 - Fair Value Disclosures - Financial Instruments (Details) - USD ($) $ in Thousands |
Jun. 30, 2022 |
Dec. 31, 2021 |
|---|---|---|
| Senior Notes Due 2025 [Member] | ||
| Aggregate Principal | $ 400,000 | $ 400,000 |
| Senior Notes Due 2025 [Member] | Fair Value, Inputs, Level 2 [Member] | ||
| Estimated Fair Value | 390,000 | 446,520 |
| Senior Notes Due 2027 [Member] | ||
| Aggregate Principal | 300,000 | 300,000 |
| Senior Notes Due 2027 [Member] | Fair Value, Inputs, Level 2 [Member] | ||
| Estimated Fair Value | 274,500 | 329,640 |
| Senior Notes Due 2029 [Member] | ||
| Aggregate Principal | 450,000 | 450,000 |
| Senior Notes Due 2029 [Member] | Fair Value, Inputs, Level 2 [Member] | ||
| Estimated Fair Value | $ 372,375 | $ 472,500 |
| X | ||||||||||
- Definition Face (par) amount of debt instrument at time of issuance. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|