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

Segment Information (Schedule Of Revenues From External Customers And Assets By Geographic Region) (Details)

Segment Information (Schedule Of Revenues From External Customers And Assets By Geographic Region) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jan. 03, 2015	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 28, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Jan. 03, 2015	Dec. 28, 2013	Dec. 29, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales to External Customers	$ 227,870us-gaap_SalesRevenueGoodsNet	$ 191,944us-gaap_SalesRevenueGoodsNet	$ 188,256us-gaap_SalesRevenueGoodsNet	$ 182,401us-gaap_SalesRevenueGoodsNet	$ 186,266us-gaap_SalesRevenueGoodsNet	$ 173,691us-gaap_SalesRevenueGoodsNet	$ 189,136us-gaap_SalesRevenueGoodsNet	$ 169,082us-gaap_SalesRevenueGoodsNet	$ 790,471us-gaap_SalesRevenueGoodsNet	$ 718,175us-gaap_SalesRevenueGoodsNet	$ 648,726us-gaap_SalesRevenueGoodsNet
Americas And Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales to External Customers									253,730	261,682	244,333
Southeast Asia/Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales to External Customers									177,940	155,362	139,651
Greater China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales to External Customers									326,134	271,812	235,626
North Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales to External Customers									32,667	29,319	29,116
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Sales to External Customers									$ 536,741	$ 456,493	$ 404,393