Annual report pursuant to Section 13 and 15(d)

Summary Of Significant Accounting Policies (Narrative) (Details)

v3.19.3.a.u2
Summary Of Significant Accounting Policies (Narrative) (Details)
 12 Months Ended
Dec. 28, 2019
USD ($)
item
Dec. 29, 2018
USD ($)
Dec. 30, 2017
USD ($)
Feb. 05, 2020
USD ($)
Summary Of Significant Accounting Policies [Line Items]        
Geographical regions | item 2      
Sub-geographical regions | item 3      
Transfers between levels $ 0 $ 0    
Non-financial assets 0      
Receivable from credit card processors 12,619,000 11,860,000    
Impairment     $ 2,734,000  
Other-than-temporary impairments $ 0      
Maturity date Feb. 01, 2024      
Notes receivable     6,734,000  
Goodwill impairment $ 0 0 0  
Impairment of indefinite-lived intangible assets 0 0 0  
Amount of individual claims before reimbursement 150,000      
Minimum amount of aggregate claims before reimbursement 10,464,000      
Self insurance program expense 11,846,000 $ 10,869,000 $ 9,195,000  
Amount available to repurchase under the stock repurchase plan $ 30,000,000      
Duration of product return for first order 30 days      
Percentage of sale refunded 100.00%      
Duration of product return 1 year      
Amount of returned product which could result in cancellation of distributorship $ 100      
Product return percentage of net sales 0.70% 0.70% 0.70%  
Advertising expense $ 11,615,000 $ 10,345,000 $ 11,503,000  
Research and development expense 10,259,000 10,242,000 8,952,000  
Derivative outstanding 0 0    
Notional amount 110,000,000 105,000,000    
Derivative gain 276,000 739,000    
Loans recovered   4,800,000    
Contract assets 0 0    
Operating, right-of-use 31,263,000      
Restricted cash 2,858,000 $ 2,908,000 $ 3,076,000  
Penalty 0      
Right-of-use assets obtained in exchange for new lease obligations 13,575,000      
Current operating lease liabilities 8,323,000      
Non-current operating lease liabilities 17,274,000      
Prepaid land use rights related to production facilities $ 6,853,000      
LIBOR [Member]        
Summary Of Significant Accounting Policies [Line Items]        
Basis point 4.00%      
Buildings [Member]        
Summary Of Significant Accounting Policies [Line Items]        
Lease expiration date 2026      
Laboratory And Production Equipment [Member]        
Summary Of Significant Accounting Policies [Line Items]        
Lease expiration date 2022      
Subsequent Event [Member]        
Summary Of Significant Accounting Policies [Line Items]        
Remaining approved repurchase amount       $ 130,000,000
Accounting Standards Update 2018-11 [Member]        
Summary Of Significant Accounting Policies [Line Items]        
Operating, right-of-use $ 19,671,000      
Right-of-use assets obtained in exchange for new lease obligations 20,010,000      
Current operating lease liabilities 7,120,000      
Non-current operating lease liabilities $ 12,890,000