Note 14 - Segment Information - Revenues and Long-lived Assets by Geographical Area (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2016		Oct. 01, 2016	[2]	Jul. 02, 2016	[3]	Apr. 02, 2016	[4]	Jan. 02, 2016		Sep. 26, 2015	[6]	Jun. 27, 2015	[7]	Mar. 28, 2015	[8]	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Net sales	$ 284,518	[1]	$ 280,331		$ 271,912		$ 219,398		$ 220,020	[5]	$ 215,510		$ 222,021		$ 210,313		$ 1,056,159	$ 867,864	$ 851,995
Long-lived assets	217,175								162,568								217,175	162,568	158,640
Additions to long-lived assets																	46,228	44,019	32,281
UNITED STATES
Net sales																	356,674	344,305	313,762
Long-lived assets	23,731								23,965								23,731	23,965	34,179
Additions to long-lived assets																	4,694	8,609	9,134
CHINA
Net sales																	263,701	193,792	189,191
Long-lived assets	65,345								37,241								65,345	37,241	40,981
Additions to long-lived assets																	13,181	9,710	7,265
Other Countries [Member]
Net sales																	435,784	329,767	349,042
Long-lived assets	118,219								90,874								118,219	90,874	70,581
Additions to long-lived assets																	28,176	25,194	15,327
CANADA
Long-lived assets	$ 9,880								$ 10,488								9,880	10,488	12,899
Additions to long-lived assets																	$ 177	$ 506	$ 555

[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.