Note 17 - Quarterly Data and Share Information (Unaudited) - Consolidated Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended									12 Months Ended
	Jan. 01, 2017	[1]	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Jan. 03, 2016	Oct. 04, 2015	Jul. 05, 2015	Apr. 05, 2015	Jan. 01, 2017		Jan. 03, 2016		Dec. 28, 2014
Net sales	$ 239,507		$ 248,349	$ 248,207	$ 222,554	$ 246,636	$ 254,686	$ 263,637	$ 236,904	$ 958,617	[2]	$ 1,001,863	[2]	$ 1,003,903	[2]
Gross profit	89,968		92,918	99,126	86,632	98,239	97,966	101,252	85,432	368,644		382,889		340,027
Net income	$ 4,707		$ 15,904	$ 20,657	$ 12,894	$ 18,247	$ 20,127	$ 21,722	$ 12,322	$ 54,162		$ 72,418		$ 24,808
Basic income per share (in dollars per share)	$ 0.07		$ 0.25	$ 0.32	$ 0.20	$ 0.28	$ 0.31	$ 0.33	$ 0.19	$ 0.83		$ 1.10		$ 0.37
Diluted income per share (in dollars per share)	0.07		0.25	0.32	0.20	0.28	0.31	0.33	0.19	0.83		1.10		$ 0.37
Maximum [Member]
High (in dollars per share)	19.10		18.45	18.71	18.99	24.44	27.17	25.59	21.38	19.10	[1]	24.44
Minimum [Member]
High (in dollars per share)	$ 14.59		$ 15.02	$ 14.56	$ 13.70	$ 17.89	$ 22.13	$ 19.86	$ 15.13	$ 14.59	[1]	$ 17.89

[1] Results for the fourth quarter of 2016 include restructuring and asset impairment charges of $19.8 million.

[2] Revenue attributed to geographic areas is based on the location of the customer.