Note 15 - Commitments and Contingencies (Details Textual) $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($)
Sites Identified	357
Sites Subject of Actions Taken by US Government	31
Sites on Superfund National Priorities List	19
Personal Injury [Member]
Recorded Liability Related to Asserted Claims	92.00%
Recorded Liability Related to Unasserted Claims	8.00%
Personal Injury [Member] | Minimum [Member]
Loss Contingency, Estimate of Possible Loss	$ 393
Personal Injury [Member] | Maximum [Member]
Loss Contingency, Estimate of Possible Loss	$ 509