Note 3 - Acquisitions (Details Textual) - USD ($) $ in Thousands					3 Months Ended																9 Months Ended	12 Months Ended
	Aug. 29, 2016	Apr. 04, 2016	Mar. 25, 2016	Oct. 01, 2015	Dec. 31, 2016	[1]	Oct. 01, 2016		Jul. 02, 2016	[3]	Apr. 02, 2016	[4]	Jan. 02, 2016	[5]	Sep. 26, 2015	[6]	Jun. 27, 2015	[7]	Mar. 28, 2015	[8]	Dec. 31, 2016	Dec. 31, 2016		Jan. 02, 2016		Dec. 27, 2014
Finite-Lived Intangible Asset, Useful Life																						12 years 328 days		12 years 146 days
Revenue, Net					$ 284,518		$ 280,331	[2]	$ 271,912		$ 219,398		$ 220,020		$ 215,510		$ 222,021		$ 210,313			$ 1,056,159		$ 867,864		$ 851,995
Goodwill, Acquired During Period																						224,140	[9]	1,470	[10]
Electronics [Member]
Revenue, Net																						535,191		405,497		410,065
Goodwill, Acquired During Period			$ 103,800																			162,172	[9]	(524)	[10]
Automotive [Member]
Revenue, Net																						415,200		339,957		$ 325,415
Goodwill, Acquired During Period			61,300																			$ 70,762	[9]	$ 1,994
Trademarks and Trade Names [Member] | Minimum [Member]
Finite-Lived Intangible Asset, Useful Life																						5 years
Trademarks and Trade Names [Member] | Maximum [Member]
Finite-Lived Intangible Asset, Useful Life																						20 years
ON Portfolio [Member]
Business Combination, Consideration Transferred	$ 104,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount	7,300
Business Acquisition Inventory Stepup	$ 700
Revenue, Net																						$ 21,800
ON Portfolio [Member] | Customer Relationships [Member]
Finite-Lived Intangible Asset, Useful Life	13 years 182 days
ON Portfolio [Member] | Patented and Unpatented Technologies [Member] | Minimum [Member]
Finite-Lived Intangible Asset, Useful Life	6 years
ON Portfolio [Member] | Patented and Unpatented Technologies [Member] | Maximum [Member]
Finite-Lived Intangible Asset, Useful Life	8 years 182 days
ON Portfolio [Member] | Noncompete Agreements [Member]
Finite-Lived Intangible Asset, Useful Life	4 years
Menber's S.p.A. [Member]
Business Combination, Consideration Transferred		$ 19,200
Business Acquisition Inventory Stepup		200
Revenue, Net																						17,300
Payments to Acquire Businesses, Gross		$ 19,162
Menber's S.p.A. [Member] | Customer Relationships [Member]
Finite-Lived Intangible Asset, Useful Life		10 years
Menber's S.p.A. [Member] | Patented and Unpatented Technologies [Member]
Finite-Lived Intangible Asset, Useful Life		5 years
Menber's S.p.A. [Member] | Trademarks and Trade Names [Member]
Finite-Lived Intangible Asset, Useful Life		10 years
PolySwitch [Member]
Business Combination, Consideration Transferred			348,292
Business Acquisition, Goodwill, Expected Tax Deductible Amount			64,900
Business Acquisition Inventory Stepup			$ 6,900
Revenue, Net																						$ 126,500
Business Acquisition, Percentage of Voting Interests Acquired			100.00%
Payments to Acquire Businesses, Gross																					$ 344,500
PolySwitch [Member] | Customer Relationships [Member]
Finite-Lived Intangible Asset, Useful Life			15 years
PolySwitch [Member] | Patented and Unpatented Technologies [Member]
Finite-Lived Intangible Asset, Useful Life			10 years
Sigmar [Member]
Business Combination, Consideration Transferred				$ 6,459
Business Acquisition, Percentage of Voting Interests Acquired				100.00%
Payments to Acquire Businesses, Gross				$ 5,558
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High							$ 900
Sigmar [Member] | Patents [Member]
Finite-Lived Intangible Asset, Useful Life				10 years

[1] In the fourth quarter of 2016, the company recorded ($0.1) million gain related to the company's transfer of its reed sensor manufacturing operations from the U.S. and China to the Philippines, $1.2 million of restructuring costs, $3.2 million in acquisition and integration costs and $0.3 million in non-cash inventory charges related to the 2016 acquisitions.

[2] In the third quarter of 2016, the company recorded $0.9 million of restructuring costs, $5.9 million in acquisition and integration costs, $14.8 million of charges related to the impairment of the custom products reporting unit and $0.5 million in non-cash inventory charges as noted above.

[3] In the second quarter of 2016, the company recorded $0.7 million related to the reed sensor manufacturing transfer as noted above, $0.1 million of restructuring costs, $6.1 million in acquisition and integration costs, $0.3 million in charges related to the closure of the manufacturing facility in Denmark and $6.9 million in non-cash inventory charges as noted above.

[4] In the first quarter of 2016, the company recorded $1.0 million related to the reed sensor manufacturing transfer as noted above, $0.4 million of restructuring costs, $6.2 million in acquisition and integration costs, and $1.6 million in charges related to the closure of the manufacturing facility in Denmark.

[5] In the fourth quarter of 2015, the company recorded $2.1 million related to the company's transfer of its reed switch manufacturing operations from the U.S. and China to the Philippines, ($0.1) million related to the reorganization of its internal legal structure, $4.0 million in acquisition costs, ($0.3) million in pension settlement refunds (See Note 10) and ($0.3) million in other.

[6] In the third quarter of 2015, the company recorded $1.2 million related to the reed switch manufacturing transfer as noted above, $0.9 million related to the company's reorganization of its internal legal structure as noted above, $0.3 million in acquisition costs, $30.8 million in pension settlement and wind-up costs (See Note 10) and $0.1 million in other.

[7] In the second quarter of 2015, the company recorded $0.9 million related to the reed switch manufacturing transfer as noted above, $1.7 million related to the company's reorganization of its internal legal structure as noted above, $0.2 million in acquisition costs, and $0.7 million in pension wind-up costs.

[8] In the first quarter of 2015, the company recorded $1.0 million related to the reed switch manufacturing transfer as noted above, $1.2 million in charges related to the reorganization of its internal legal structure as noted above, $0.2 million in acquisition costs, and $0.7 million in pension wind-up costs.

[9] Included The net additions of $224,140 resulted primarily from the acquisitions of PolySwitch, ON and Menber's, partially offset by the impairment of custom products reporting unit goodwill.

[10] Electronics reduction resulted from reclassification of goodwill to customer relationships. Automotive addition of $2.0 million resulted from business acquisitions.