Quarterly report pursuant to Section 13 or 15(d)

Equity-Based Compensation (Narrative) (Details)

v2.4.1.9
Equity-Based Compensation (Narrative) (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended
Apr. 04, 2015
Mar. 29, 2014
Jan. 03, 2015
Equity-Based Compensation [Abstract]      
Equity-based compensation expense $ 2,210us-gaap_AllocatedShareBasedCompensationExpense $ 1,836us-gaap_AllocatedShareBasedCompensationExpense  
Equity-based compensation related tax benefit 740us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense 617us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense  
Weighted-average grant date fair value $ 30.49us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue $ 17.73us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue  
Total intrinsic value of stock options and stock-settled stock appreciation rights exercised 3,345us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue 6,800us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue  
Total fair value of equity awards vested $ 811us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue $ 496us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue  
Closing Price Of Common Stock $ 114.19usna_ClosingPriceOfCommonStock   $ 102.28usna_ClosingPriceOfCommonStock