Annual report pursuant to Section 13 and 15(d)

Deferred Compensation (Narrative) (Details)

v2.4.1.9
Deferred Compensation (Narrative) (Details) (Former Officers [Member], USD $)
In Thousands, unless otherwise specified
12 Months Ended
Jan. 03, 2015
Dec. 28, 2013
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]    
Minimum period of deferred compensation benefits (years) 10 years  
Minimum deferred compensation benefit age (years) 65 years  
Estimate of Fair Value, Fair Value Disclosure [Member]
   
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]    
Present value of vested future deferred compensation payments 261us-gaap_DeferredCompensationLiabilityCurrentAndNoncurrent
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
/ us-gaap_TitleOfIndividualAxis
= synl_FormerOfficersMember
$ 271us-gaap_DeferredCompensationLiabilityCurrentAndNoncurrent
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
/ us-gaap_TitleOfIndividualAxis
= synl_FormerOfficersMember