Note 10 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Tax Expense (Benefit), Total	$ 96	$ 151	$ 624	$ 976
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	(21,398)	(7,398)	(38,258)	(23,244)
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount			0
Deferred Tax Assets, Valuation Allowance, Total	0		0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense, Total	$ 0	$ 0	$ 0	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%		35.00%
Tax Cuts and Jobs Act of 2017 Incomplete Accounting Change in Tax Rate Deferred Tax Asset Provisional Income Tax Benefit			$ 18,696
Tax Cuts and Jobs Act of 2017 Incomplete Accounting Change in Tax Rate Deferred Tax Liability Provisional Income Tax Benefit			4,394
Tax Cuts and Jobs Act of 2017 Incomplete Accounting Change in Tax Rate Valuation Allowance Provisional Income Tax Benefit			$ 14,302