Note 14 - Commitments and Contingencies (Details Textual)
|3 Months Ended|
Mar. 31, 2018
|Environmental Remediation Expense||$ 700,000|
|Fine Paid to US EPA||$ 6,000|
The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities.
Reference 1: http://www.xbrl.org/2003/role/disclosureRef