Note 14 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Income Tax Expense (Benefit), Total	$ 200,000	$ 7,999,000
Effective Income Tax Rate Reconciliation, Percent, Total	(7.42%)	38.80%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount, Total	$ 855,000	$ 49,000
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent, Total	(31.68%)
Equity Securities, FV-NI, Unrealized Gain (Loss), Total	$ (15,517,000)
Effective Income Tax Rate Reconciliation, Tax Contingency, Amount, Total		175,000
Effective Income Tax Rate Reconciliation, Exercise of Stock Options, Amount		$ 124,000
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			$ (8,488,000)
Earliest Tax Year [Member]
Open Tax Year	2014