Annual report pursuant to Section 13 and 15(d)

Equity-Based Compensation (Schedule Of Stock Option Activity) (Details)

v2.4.1.9
Equity-Based Compensation (Schedule Of Stock Option Activity) (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
12 Months Ended
Jan. 03, 2015
Dec. 28, 2013
Equity-Based Compensation [Abstract]    
Shares, Outstanding 1,827us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber  
Shares, Granted 786us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross  
Shares, Exercised (958)us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised  
Shares, Cancelled (100)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod  
Shares, Outstanding 1,555us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber 1,827us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Shares, Exercisable 67us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber  
Weighted-average grant price, Outstanding $ 37.37us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice  
Weighted-average grant price, Granted $ 60.61us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice  
Weighted-average grant price, Exercised $ 36.02us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice  
Weighted-average grant price, Cancelled $ 49.01us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice  
Weighted-average grant price, Outstanding $ 49.20us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice $ 37.37us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Weighted-average grant price, Exercisable $ 36.14us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice  
Weighted-average remaining contractual term, Outstanding 2 years 10 months 24 days 2 years 7 months 6 days
Weighted-average remaining contractual term, Exercisable 2 years 2 months 12 days  
Aggregate intrinsic value, Outstanding $ 74,160us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue  
Aggregate intrinsic value, Outstanding 82,564us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue 74,160us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
Aggregate intrinsic value, Exercisable $ 4,444us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1  
Closing price of common stock $ 102.28usna_ClosingPriceOfCommonStock $ 77.72usna_ClosingPriceOfCommonStock