Note 2 - Summary of Significant Accounting Policies (Tables)
|12 Months Ended|
Dec. 31, 2016
|Schedule of Credit Losses for Financing Receivables, Current [Table Text Block]||
Tabular disclosure of credit losses for current financing receivables (such as trade and accounts receivable), including a rollforward of the balance. An alternative caption includes allowance for doubtful accounts.
Reference 1: http://www.xbrl.org/2003/role/presentationRef