Note 13 - Income Taxes (Details Textual) - USD ($)		12 Months Ended
	Dec. 22, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%		21.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			$ 100,000	$ (82,900,000)
Deferred Tax Assets, Valuation Allowance, Total		$ 121,000	50,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		3,000,000.0	2,400,000
Unrecognized Tax Benefits, Interest on Income Taxes Expense		5,220	(27,450)	21,050
Unrecognized Tax Benefits, Income Tax Penalties Accrued		0
Unrecognized Tax Benefits, Interest on Income Taxes Accrued		144,000	$ 139,000	$ 166,000
Undistributed Earnings of Foreign Subsidiaries		1,300,000
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount		$ 0
Effective Income Tax Rate Reconciliation, Dividend Received Deduction, Percent		100.00%
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total		$ 48,300,000
Deferred Tax Assets, Operating Loss Carryforwards, Total		$ 2,300,000
Open Tax Year		2015 2016 2017 2018 2019
State and Local Jurisdiction [Member] | Deferred Tax Assets Related to Operating Loss Carryforwards [Member]
Deferred Tax Assets, Valuation Allowance, Total		$ 121,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ 71,000
Domestic Tax Authority [Member]
Open Tax Year		2016 2017 2018 2019