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 |