Note 3 - Income Taxes (Details Textual) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Deferred Tax Liabilities, Net		$ 78.0
Deferred Tax Assets, Valuation Allowance		72.0	$ 100.0
Internal Revenue Service (IRS) [Member] | Domestic Tax Authority [Member]
Deferred Tax Assets, Net		44.7
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ (15.0)
Canada Revenue Agency [Member] | Foreign Tax Authority [Member]
Deferred Tax Liabilities, Net		$ 122.7