For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Note 9 - Significant Customers, Concentration of Credit Risk, and Geographic Information (Details Textual) - Customer Concentration Risk [Member]	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Dec. 31, 2018
Revenue Benchmark [Member]
Number of Major Customers Concentration Risk	2
Revenue Benchmark [Member] \| Customer 1 [Member]
Concentration Risk, Percentage	20.70%
Revenue Benchmark [Member] \| Customer 2 [Member]
Concentration Risk, Percentage	11.00%
Accounts Receivable [Member]
Concentration Risk, Percentage		36.70%	31.90%	6.30%
Number of Major Customers Concentration Risk	2		2	2
Accounts Receivable [Member] \| Customer 1 [Member]
Concentration Risk, Percentage			23.50%
Accounts Receivable [Member] \| Customer 2 [Member]
Concentration Risk, Percentage			11.00%