Note 1 - Summary of Significant Accounting Policies (Details Textual)					1 Months Ended	3 Months Ended			6 Months Ended
		Dec. 28, 2019 USD ($)		Oct. 01, 2019 USD ($)	Jun. 27, 2020 USD ($)	Jun. 27, 2020 USD ($) shares	Mar. 28, 2020 USD ($)	Jun. 29, 2019 USD ($) shares	Jun. 27, 2020 USD ($) shares	Jun. 29, 2019 USD ($) shares	Mar. 30, 2019 USD ($)	Dec. 30, 2018 USD ($)	Dec. 29, 2018 USD ($)
Number of Operating Segments									4
Number of Reportable Segments									2
Goodwill and Intangible Asset Impairment, Total				$ 0
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)						$ 0		$ 0	$ 3,949,000	$ 0
Amortization of Debt Issuance Costs						300,000		300,000	600,000	500,000
Foreign Currency Transaction Gain (Loss), Realized						$ (600,000)		$ (500,000)	$ (1,000,000.0)	$ (300,000)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) | shares						286,000		610,000	172,000	502,000
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance		$ 483,072,000			$ 466,758,000	$ 466,758,000	$ 464,884,000	$ 514,449,000	$ 466,758,000	$ 514,449,000	$ 528,314,000		$ 545,944,000
Assets, Total		1,077,710,000	[1]		1,066,583,000	1,066,583,000			1,066,583,000
Revenue, Remaining Performance Obligation, Amount					9,200,000	9,200,000			9,200,000
Deferred Income		16,100,000			18,600,000	18,600,000			18,600,000
Deferred Profit		7,645,000	[1]		9,614,000	9,614,000			9,614,000
Deferred Profit Long-term		7,200,000			6,900,000	6,900,000			6,900,000
Accumulated Other Comprehensive Income (Loss), Net of Tax, Total		(34,030,000)	[1]		(33,062,000)	(33,062,000)			(33,062,000)
Retained Earnings [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance		$ 42,517,000			18,015,000	$ 18,015,000	22,755,000	$ 75,115,000	$ 18,015,000	$ 75,115,000	$ 96,938,000		111,670,000
Accounting Standards Update 2016-02 [Member]
Assets, Total												$ (500,000)
Liabilities, Total												(600,000)
Accounting Standards Update 2016-02 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance	[2]												10,352,000
Accounting Standards Update 2016-02 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Retained Earnings [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance												$ 10,200,000	$ 10,352,000	[2]
Indefinite-lived In Process Research and Development [Member]
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)							$ 3,900,000
Minimum [Member]
Standard Product Warranty Term (Month)									12 months
Maximum [Member]
Standard Product Warranty Term (Month)									36 months
Building [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)									30 years
Building [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)									40 years
Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)									5 years
Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)									15 years
Machinery, Equipment and Software [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)									3 years
Machinery, Equipment and Software [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)									10 years
Selling, General and Administrative Expenses [Member] | Facility in Penang Malaysia [Member]
Gain (Loss) on Disposition of Property Plant Equipment, Total					$ 27,000
ALBS [Member]
Variable Interest Entity, Ownership Percentage Sold		20.00%

[1] Derived from December 28, 2019 audited financial statements

[2] Cumulative effect of accounting change relates to our adoption of ASU 2016-02. Please refer to Note 1 of the Condensed Consolidated Financial Statements for further detail on the adoption of this accounting standard.