Note 14 - Commitments and Contingencies (Details Textual) $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)
Sites Identified	349
Sites Subject of Actions Taken by US Government	32
Sites on Superfund National Priorities List	20
Personal Injury [Member]
Recorded Liability Related to Asserted Claims	95.00%
Recorded Liability Related to Unasserted Claims	5.00%
Personal Injury [Member] | Minimum [Member]
Loss Contingency, Estimate of Possible Loss	$ 376
Personal Injury [Member] | Maximum [Member]
Loss Contingency, Estimate of Possible Loss	$ 487