Note 7 - Debt (Tables)
|6 Months Ended|
Jun. 30, 2017
|Schedule of Maturities of Long-term Debt [Table Text Block]||
Tabular disclosure of the combined aggregate amount of maturities and sinking fund requirements for all long-term borrowings for each of the five years following the date of the latest balance sheet date presented.
Reference 1: http://www.xbrl.org/2003/role/presentationRef