Segment Information (Percentage Of Total Product Revenue Contributed By Company's Nutritional And Care Products) (Details)	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
USANA Nutritionals [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	79.00%	80.00%
USANA Foods [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	13.00%	12.00%
Sense - Beautiful Science [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	6.00%	6.00%