Note 11 - Income Taxes (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 22, 2017	Dec. 31, 2017	Jan. 01, 2017	Dec. 31, 2017	Jan. 01, 2017	Jun. 30, 2019	Jul. 01, 2018
Effective Income Tax Rate Reconciliation, Percent		15.20%	33.30%	8.70%	32.60%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		$ (15,900)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Per Diluted Share		$ (0.24)
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability		$ (12,200)
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability, Per Diluted Share		$ (0.18)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Tax Adjustments, Settlements, and Unusual Provisions		$ (3,700)
Tax Adjustments, Settlements, and Unusual Provisions, Per Diluted Share		$ (0.06)
Unrecognized Tax Benefits		$ 400		$ 400
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit		$ 0		$ 0
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent						21.00%	28.00%