Note 18 - Concentration of Risk in Customer and Supplier Relationships (Details) - Percentages of Sales to Largest Customers - Sales Revenue, Goods, Net [Member] - Customer Concentration Risk [Member] |
12 Months Ended | |
|---|---|---|
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Smart Energy Today [Member] | ||
| Concentration Risk [Line Items] | ||
| Percentage of sales | 13.30% | 13.50% |
| WDC Solar, Inc. [Member] | ||
| Concentration Risk [Line Items] | ||
| Percentage of sales | 12.00% | 14.70% |
| JCF Wholesale [Member] | ||
| Concentration Risk [Line Items] | ||
| Percentage of sales | 8.70% | 10.60% |
| Lowe's Companies, Inc. [Member] | ||
| Concentration Risk [Line Items] | ||
| Percentage of sales | 5.90% | 6.90% |
| Sustainable Environmental Enterprises [Member] | ||
| Concentration Risk [Line Items] | ||
| Percentage of sales | 1.30% | 52.80% |