USANA Health Sciences, Inc. Annual report pursuant to Section 13 and 15(d)

Segment Information (Schedule Of Long-Lived Assets By Geographic Region) (Details) - USD ($) $ in Thousands	Dec. 28, 2019	Dec. 29, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 184,565	$ 158,780
Assets	516,934	554,463
Greater China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	95,569	92,062
Assets	254,997	301,498
Southeast Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	16,630	13,042
Assets	49,786	45,495
North Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	10,466	3,311
Assets	21,903	14,186
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	122,665	108,415
Assets	326,686	361,179
Americas And Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	61,900	50,365
Assets	$ 190,248	$ 193,284