Note 12 - Dispositions and Acquisitions (Details Textual) - USD ($) $ in Thousands				12 Months Ended
Mar. 01, 2019	May 21, 2018	Feb. 28, 2018	Dec. 31, 2019	Dec. 31, 2018
Proceeds from Sale of Productive Assets, Total	$ 1,300	$ 3,300	$ 23,000	$ 1,334	$ 26,839
Other Miscellaneous Acreage [Member]
Proceeds from Sale of Productive Assets, Total					$ 700

The cash inflow from the sale of property, plant and equipment (capital expenditures), software, and other intangible assets.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585

Name:	us-gaap_ProceedsFromSaleOfProductiveAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration