Annual report pursuant to Section 13 and 15(d)

Segment Information (Schedule Of Long-Lived Assets By Geographic Region) (Details)

v2.4.1.9
Segment Information (Schedule Of Long-Lived Assets By Geographic Region) (Details) (USD $)
In Thousands, unless otherwise specified
Jan. 03, 2015
Dec. 28, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]    
Long-lived Assets $ 153,724us-gaap_NoncurrentAssets $ 133,906us-gaap_NoncurrentAssets
Assets 350,584us-gaap_Assets 368,470us-gaap_Assets
North America/Europe [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Long-lived Assets 54,457us-gaap_NoncurrentAssets
/ us-gaap_StatementGeographicalAxis
= usna_NorthAmericaAndEuropeMember
52,908us-gaap_NoncurrentAssets
/ us-gaap_StatementGeographicalAxis
= usna_NorthAmericaAndEuropeMember
Assets 152,405us-gaap_Assets
/ us-gaap_StatementGeographicalAxis
= usna_NorthAmericaAndEuropeMember
183,561us-gaap_Assets
/ us-gaap_StatementGeographicalAxis
= usna_NorthAmericaAndEuropeMember
Southeast Asia/Pacific [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Long-lived Assets 14,175us-gaap_NoncurrentAssets
/ us-gaap_StatementGeographicalAxis
= usna_SoutheastAsiaAndPacificMember
15,868us-gaap_NoncurrentAssets
/ us-gaap_StatementGeographicalAxis
= usna_SoutheastAsiaAndPacificMember
Assets 38,404us-gaap_Assets
/ us-gaap_StatementGeographicalAxis
= usna_SoutheastAsiaAndPacificMember
36,349us-gaap_Assets
/ us-gaap_StatementGeographicalAxis
= usna_SoutheastAsiaAndPacificMember
Greater China [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Long-lived Assets 83,471us-gaap_NoncurrentAssets
/ us-gaap_StatementGeographicalAxis
= usna_GreaterChinaMember
63,505us-gaap_NoncurrentAssets
/ us-gaap_StatementGeographicalAxis
= usna_GreaterChinaMember
Assets 154,153us-gaap_Assets
/ us-gaap_StatementGeographicalAxis
= usna_GreaterChinaMember
141,542us-gaap_Assets
/ us-gaap_StatementGeographicalAxis
= usna_GreaterChinaMember
North Asia [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Long-lived Assets 1,621us-gaap_NoncurrentAssets
/ us-gaap_StatementGeographicalAxis
= usna_NorthAsiaMember
1,625us-gaap_NoncurrentAssets
/ us-gaap_StatementGeographicalAxis
= usna_NorthAsiaMember
Assets 5,622us-gaap_Assets
/ us-gaap_StatementGeographicalAxis
= usna_NorthAsiaMember
7,018us-gaap_Assets
/ us-gaap_StatementGeographicalAxis
= usna_NorthAsiaMember
Asia Pacific [Member]    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Long-lived Assets 99,267us-gaap_NoncurrentAssets
/ us-gaap_StatementGeographicalAxis
= us-gaap_AsiaPacificMember
80,998us-gaap_NoncurrentAssets
/ us-gaap_StatementGeographicalAxis
= us-gaap_AsiaPacificMember
Assets $ 198,179us-gaap_Assets
/ us-gaap_StatementGeographicalAxis
= us-gaap_AsiaPacificMember
$ 184,909us-gaap_Assets
/ us-gaap_StatementGeographicalAxis
= us-gaap_AsiaPacificMember