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Segment Information (Schedule Of Revenue Percentage By Product) (Details)	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
USANA Nutritionals [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	83.00%	83.00%	81.00%
USANA Foods [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	9.00%	10.00%	11.00%
Sense - Beautiful Science [Member]
Revenue from External Customer [Line Items]
Percentage of product revenue	6.00%	6.00%	7.00%

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

Percentage Of Product Revenue

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- Details

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X

- Details

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X

- Details

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