Segment Information (Schedule Of Revenue Percentage By Product) (Details)	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
USANA Nutritionals [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	80.00%	79.00%	77.00%
USANA Foods [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	11.00%	11.00%	12.00%
Sense - Beautiful Science [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	7.00%	7.00%	8.00%