Note 8 - Segment Information (Details Textual)	3 Months Ended
Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)
Number of Reportable Segments	4
Corporate, Non-Segment [Member]
Gross Profit, Total	$ 6,827,000	$ 6,726,000

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1,2)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

Name:	us-gaap_GrossProfit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration