Note 11 - Accumulated Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Foreign currency translation adjustments, before tax	$ (5,789)	$ (11,000)	$ (14,107)
Foreign currency translation adjustments, tax
Foreign currency translation adjustments, net of tax	(5,789)	(11,000)	(14,107)
Adjustments related to postretirement benefits, before tax	(429)	(24)	(3,809)
Adjustments related to postretirement benefits, tax	113	(34)	551
Adjustments related to postretirement benefits, net of tax	(316)	(58)	(3,258)
Other comprehensive income (loss), before tax	(6,223)	(11,024)	(17,916)
Other comprehensive income (loss), tax	113	(34)	551
Other comprehensive income (loss), net of tax	(6,110)	(11,058)	(17,365)
Change in unrealized gain/loss on investments, before tax	(5)
Change in unrealized gain/loss on investments, tax
Change in unrealized gain/loss on investments, net of tax	$ (5)

Amount before tax, after reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans, attributable to parent entity.

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