Note 6 - Goodwill and Intangible Assets (Details Textual) $ in Millions	9 Months Ended
	Sep. 30, 2018 USD ($)
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	$ 1
Finite-Lived Intangible Assets, Amortization Expense, Year Four	1
Finite-Lived Intangible Assets, Amortization Expense, Year Three	1
Finite-Lived Intangible Assets, Amortization Expense, Year Two	1
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 1
Customer Relationships [Member]
Finite-Lived Intangible Asset, Useful Life	15 years
Finite-Lived Intangible Assets, Remaining Amortization Period	15 years