Note 15 - Accumulated Other Comprehensive Loss - Components of Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Foreign currency translation adjustments, before tax	$ 27,321	$ (7,522)	$ (8,905)
Foreign currency translation adjustments, tax	0	0	0
Foreign currency translation adjustments, net of tax	27,321	(7,522)	(8,905)
Adjustments related to postretirement benefits, before tax	2,599	(856)	865
Adjustments related to postretirement benefits, tax	(216)	228	(60)
Adjustments related to postretirement benefits, net of tax	2,383	(628)	805
Change in unrealized gain/loss on investments, before tax			7
Change in unrealized gain/loss on investments, tax			0
Change in unrealized gain/loss on investments, net of tax	0	0	7
Other comprehensive income (loss), before tax	29,920	(8,378)	(8,033)
Other comprehensive income (loss), tax	(216)	228	(60)
Other comprehensive income (loss), net of tax	$ 29,704	$ (8,150)	$ (8,093)

Amount, before tax, after reclassification adjustment, of (increase) decrease in accumulated other comprehensive (income) loss for defined benefit plan, attributable to parent entity.

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