Segment Information (Percentage Of Total Product Revenue Contributed By Company's Nutritional And Care Products) (Details)	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jun. 28, 2014	Jul. 04, 2015	Jun. 28, 2014
USANA Nutritionals [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	81.00%	78.00%	81.00%	79.00%
USANA Foods [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	12.00%	14.00%	12.00%	13.00%
Sense - Beautiful Science [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	6.00%	7.00%	6.00%	7.00%