Segment Information (Percentage Of Total Product Revenue Contributed By Company's Nutritional And Care Products) (Details)	12 Months Ended
	Jan. 02, 2016	Jan. 03, 2015	Dec. 28, 2013
USANA Nutritionals [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	81.00%	79.00%	80.00%
USANA Foods [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	11.00%	13.00%	11.00%
Sense - Beautiful Science [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	7.00%	7.00%	6.00%