Segment Information (Percentage Of Total Product Revenue Contributed By Company's Nutritional And Care Products) (Details)	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
USANA Nutritionals [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	80.00%	80.00%
USANA Foods [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	12.00%	11.00%
Sense - Beautiful Science [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	6.00%	7.00%