Note 10 - Segment Information - Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016
Net sales		$ 313,355	$ 271,912	$ 598,797	$ 491,310
Depreciation and amortization		15,617	14,081	30,690	25,108
Operating income		60,270	29,702	109,123	62,130
Interest expense		3,281	1,670	6,401	3,715
Foreign exchange loss (gain)		(558)	(6,237)	(2,115)	(2,414)
Other expense (income), net		190	255	52	(262)
Income before income taxes		57,357	34,014	104,785	61,091
Electronics [Member]
Net sales		169,387	132,170	323,154	230,966
Depreciation and amortization		8,707	7,717	17,095	13,089
Operating income		42,967	25,259	78,173	47,675
Automotive [Member]
Net sales		116,457	111,370	224,297	203,303
Depreciation and amortization		5,580	4,988	10,950	8,254
Operating income		15,713	16,474	30,778	33,965
Industrial [Member]
Net sales		27,511	28,372	51,346	57,041
Depreciation and amortization		1,330	1,376	2,645	2,828
Operating income		1,905	2,028	2,012	3,701
Other Segments [Member]
Depreciation and amortization					937
Operating income	[1]	$ (315)	$ (14,059)	$ (1,840)	$ (23,211)

[1] Included in "Other" Operating income (loss) for the 2017 second quarter is of $0.3 million ($1.8 million year-to-date) of acquisition and integration costs associated with the Company's 2016 acquisitions (included in Cost of sales ("COS") and Selling, general, and administrative expenses ("SG&A)). Included in "Other" Operating income (loss) for the 2016 second quarter is $6.1 million ($12.3 million year-to-date) of acquisition-related costs primarily related to legal and integration costs associated with the company's acquisition of the PolySwitch business, a $6.9 million ($6.9 million year-to-date) inventory adjustment relating to the PolySwitch acquisition as described in Note 4, $0.3 million ($1.9 million year-to-date) in charges related to the closure of the company's manufacturing facility in Denmark, $0.7 million ($1.7 million year-to-date) related to the company's transfer of its reed sensor manufacturing operations from the U.S. and China to the Philippines and $0.1 million ($0.4 million year-to-date) related to internal legal restructuring costs.