Note A - Organization, Consolidation, and Basis of Presentation (Details Textual)	9 Months Ended
Sep. 26, 2020
Number of Geographic Regions	2
Number of Sub Geographical Regions	3

The number of sub-geogaphical regions the company operates in.

No definition available.

Name:	usna_NumberOfSubGeographicalRegions
Namespace Prefix:	usna_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration