Note 3 - Fair Value Measurements - Fair Value and Carrying Value of the Notes (Details) - Senior Notes [Member] - USD ($) $ in Thousands |
Sep. 30, 2019 |
Mar. 31, 2019 |
---|---|---|
Reported Value Measurement [Member] | ||
Notes | $ 137,682 | |
Estimate of Fair Value Measurement [Member] | ||
Notes | ||
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | ||
Notes | $ 184,575 |