Business Segment, Geographic And Concentration Risk Information (Sales by Geographic Information) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Jan. 01, 2016	Oct. 02, 2015	Jul. 03, 2015	Apr. 03, 2015	Dec. 30, 2016	Jan. 01, 2016	Jan. 02, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	$ 359,591	$ 346,567	$ 348,382	$ 332,238	$ 317,567	$ 146,637	$ 174,890	$ 161,320	$ 1,386,778	$ 800,414	$ 687,787
UNITED STATES [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales									805,742	401,380	312,539
PUERTO RICO [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales									159,243	136,898	127,702
BELGIUM [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales									69,149	62,546	65,308
Rest Of World [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales									$ 352,644	$ 199,590	$ 182,238