Note 11 - Business Unit Segment Information (Details) - Net Sales by Geographic Area (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 27, 2014		Sep. 28, 2013		Sep. 27, 2014		Sep. 28, 2013
Note 11 - Business Unit Segment Information (Details) - Net Sales by Geographic Area [Line Items]
Net sales	$ 217,608	[1]	$ 201,040	[1]	$ 645,375	[1]	$ 559,724	[1]
UNITED STATES
Note 11 - Business Unit Segment Information (Details) - Net Sales by Geographic Area [Line Items]
Net sales	85,326	[1]	76,183	[1]	243,979	[1]	202,731	[1]
CHINA
Note 11 - Business Unit Segment Information (Details) - Net Sales by Geographic Area [Line Items]
Net sales	45,905	[1]	43,644	[1]	134,166	[1]	114,952	[1]
Other Countries [Member]
Note 11 - Business Unit Segment Information (Details) - Net Sales by Geographic Area [Line Items]
Net sales	$ 86,377	[1]	$ 81,213	[1]	$ 267,230	[1]	$ 242,041	[1]

[1] Sales by country represent sales to customer or distributor locations.