Note 10 - Fair Value Measurements - Recurring Fair Value Measurements (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2025	Mar. 31, 2025
Total	$ 848	$ 349
Swap [Member]
Commodity swap contracts – financial assets, net	920	349
Future [Member]
Commodity swap contracts – financial assets, net	(72)
Fair Value, Inputs, Level 1 [Member]
Total	(72)	349
Fair Value, Inputs, Level 1 [Member] | Swap [Member]
Commodity swap contracts – financial assets, net	0	349
Fair Value, Inputs, Level 1 [Member] | Future [Member]
Commodity swap contracts – financial assets, net	(72)
Fair Value, Inputs, Level 2 [Member]
Total	920	0
Fair Value, Inputs, Level 2 [Member] | Swap [Member]
Commodity swap contracts – financial assets, net	920	0
Fair Value, Inputs, Level 2 [Member] | Future [Member]
Commodity swap contracts – financial assets, net	0
Fair Value, Inputs, Level 3 [Member]
Total	0	0
Fair Value, Inputs, Level 3 [Member] | Swap [Member]
Commodity swap contracts – financial assets, net	0	$ 0
Fair Value, Inputs, Level 3 [Member] | Future [Member]
Commodity swap contracts – financial assets, net	$ 0