Note 7 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%	35.00%	35.00%
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount			$ (1,100,000)
Capital Loss Carryforwards				$ 3,100,000
Deferred Tax Assets, Valuation Allowance				$ 1,100,000
Undistributed Earnings of Foreign Subsidiaries	$ 15,200,000
Potential Income Tax Related to Repatriation of Foreign Earnings	536,000
Unrecognized Tax Benefits, Excluding Interest and Penalties	463,000	$ 450,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	4,000	10,000
Unrecognized Tax Benefits, Income Tax Penalties Accrued	7,000	7,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	119,000	244,000
Unrecognized Tax Benefits that Would Not Impact Effective Tax Rate	344,000	206,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense (Reduction)	(6,000)	$ 2,000
Reclassification from Current Deferred Tax Assets to Noncurrent Deferred Tax Assets [Member] | December 31, 2015 [Member]
Prior Period Reclassification Adjustment	$ 1,100,000