Note 1 - General (Details Textual) - Accounting Standards Update 2014-09 [Member] $ in Thousands	9 Months Ended
Sep. 30, 2018 USD ($)
Nine Months Ended September 30, 2017 [Member]
Prior Period Reclassification Adjustment	$ 2,093
Three Months Ended September 30, 2017 [Member]
Prior Period Reclassification Adjustment	$ 715

The amount of a reclassification adjustment made to prior period financial statement amounts.

No definition available.

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