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

Segment Information (Consolidated Net Sales And Long Lived Assets By Percent) (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	$ 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
Long-lived Assets	153,724us-gaap_NoncurrentAssets				133,906us-gaap_NoncurrentAssets				153,724us-gaap_NoncurrentAssets	133,906us-gaap_NoncurrentAssets
China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									216,842	106,710
Long-lived Assets	81,704				61,716				81,704	61,716
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									143,669	157,543	152,460
Long-lived Assets	53,322				51,260				53,322	51,260
Hong Kong [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales										$ 132,285	$ 180,837