Note 7 - Guarantees and Other Obligations - Changes in Accrued Warranty (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Balance at beginning of period	$ 4,948	$ 5,070	$ 4,848	$ 4,350
Warranty expense accruals	1,600	1,720	4,988	5,446
Warranty payments	(1,946)	(1,773)	(5,234)	(4,829)
Warranty liability assumed				50
Balance at end of period	$ 4,602	$ 5,017	$ 4,602	$ 5,017

Carrying value as of the balance sheet date of obligations incurred through that date and payable for estimated claims under standard and extended warranty protection rights granted to customers.

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Amount of increase in the standard and extended product warranty accrual from a business acquisition.

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Amount of decrease in the standard and extended product warranty accrual from payments made in cash or in kind to satisfy claims under the terms of the standard and extended product warranty.

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Amount of increase in the standard and extended product warranty accrual from warranties issued.

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