Note 9 - Income Taxes (Details Textual) - USD ($)			3 Months Ended		12 Months Ended
	Jan. 01, 2018	Dec. 22, 2017	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2018
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			$ (16,000,000)
Income Tax Expense (Benefit), Continuing Operations, Revaluation Differences in Deferred Taxes			(20,000,000)
Income Tax Expense (Benefit)			(16,850,000)	$ (310,000)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest			$ (2,111,000)	$ (1,781,000)
Effective Income Tax Rate Reconciliation, Percent			798.00%	17.00%
Domestic Tax Authority [Member] | Earliest Tax Year [Member]
Open Tax Year			2015
State and Local Jurisdiction [Member] | Earliest Tax Year [Member]
Open Tax Year			2013
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent					24.28%
Subsequent Event [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%