Note 10 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019	Dec. 28, 2019
Income Tax Expense (Benefit), Total	$ 444	$ 234
Unrecognized Tax Benefits, Ending Balance	2,300
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total	500
Decrease in Unrecognized Tax Benefits is Reasonably Possible	2,800
Deferred Tax Liabilities, Net, Total	24,800
Other Noncurrent Liabilities [Member]
Liability for Uncertainty in Income Taxes, Noncurrent	$ 24,300		$ 24,600
Domestic Tax Authority [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Foreign Tax Authority [Member]
Deferred Tax Assets, Valuation Allowance, Total	$ 0
Foreign Tax Authority [Member] | Office of the Tax Commissioner, Bermuda [Member]
Income Tax Expense (Benefit), Total		$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	0.00%	0.00%