Note 1 - Basis of Presentation (Details Textual) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018
Increase (Decrease) in Contract with Customer, Liability	$ 444	$ 286
Increase (Decrease) in Accrued Liabilities, Total	$ 30	(1,005)
Restatement Adjustment [Member]
Increase (Decrease) in Contract with Customer, Liability		(573)
Increase (Decrease) in Accrued Liabilities, Total		$ (573)

Amount of increase (decrease) in obligation to transfer good or service to customer for which consideration has been received or is receivable.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

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