| 
           Environmental Compliance Costs (Details) (USD $) 
        In Thousands, unless otherwise specified  | 
        12 Months Ended | ||||
|---|---|---|---|---|---|
| 
           Jan. 03, 2015 
         | 
        
           Jan. 02, 2010 
         | 
        
           Jan. 01, 2011 
         | 
        
           Dec. 28, 2013 
         | 
        
           Dec. 31, 2000
 
          solid_waste_management_units 
         | 
      |
| Environmental Exit Cost [Line Items] | |||||
| Environmental remediation reserves | 576us-gaap_AccrualForEnvironmentalLossContingencies | $ 626us-gaap_AccrualForEnvironmentalLossContingencies | |||
| Minimum [Member] | |||||
| Environmental Exit Cost [Line Items] | |||||
| Environmental remediation costs, period of recognition (years) | 3 years | ||||
| Maximum [Member] | |||||
| Environmental Exit Cost [Line Items] | |||||
| Environmental remediation costs, period of recognition (years) | 4 years | ||||
| Comprehensive Environmental Response, Compensation, and Liability Act [Member] | |||||
| Environmental Exit Cost [Line Items] | |||||
| Number of environmental remediation sites (sites) | 
2synl_SiteContingencyNumberOfSites / us-gaap_LitigationCaseAxis = synl_ComprehensiveEnvironmentalResponseCompensationAndLiabilityActMember  | 
        ||||
| Spartanburg Plant [Member] | |||||
| Environmental Exit Cost [Line Items] | |||||
| Number of solid waste management units | 
14synl_NumberOfSolidWasteManagementUnits / us-gaap_EnvironmentalRemediationSiteAxis = synl_SpartanburgPlantMember  | 
      ||||
| Environmental charges | 
968us-gaap_EnvironmentalRemediationExpense / us-gaap_EnvironmentalRemediationSiteAxis = synl_SpartanburgPlantMember  | 
        ||||
| Augusta Plant [Member] | |||||
| Environmental Exit Cost [Line Items] | |||||
| Environmental remediation reserves | 
501us-gaap_AccrualForEnvironmentalLossContingencies / us-gaap_EnvironmentalRemediationSiteAxis = synl_AugustaPlantMember  | 
        
551us-gaap_AccrualForEnvironmentalLossContingencies / us-gaap_EnvironmentalRemediationSiteAxis = synl_AugustaPlantMember  | 
        |||
| Bristol, Tennessee Facility [Member] | |||||
| Environmental Exit Cost [Line Items] | |||||
| Environmental remediation reserves | 
75us-gaap_AccrualForEnvironmentalLossContingencies / us-gaap_EnvironmentalRemediationSiteAxis = synl_BristolTennesseeFacilityMember  | 
        
75us-gaap_AccrualForEnvironmentalLossContingencies / us-gaap_EnvironmentalRemediationSiteAxis = synl_BristolTennesseeFacilityMember  | 
        |||
| Number of solid waste management units | 
2synl_NumberOfSolidWasteManagementUnits / us-gaap_EnvironmentalRemediationSiteAxis = synl_BristolTennesseeFacilityMember  | 
        ||||
| Superfund Site [Member] | |||||
| Environmental Exit Cost [Line Items] | |||||
| De minimis environmental remediation settlement | 
$ 2synl_DeMinimisEnvironmentalRemediationSettlement / us-gaap_EnvironmentalRemediationSiteAxis = synl_SuperfundSiteMember  | 
        ||||
| X | ||||||||||
| 
             
- Definition 
          De Minimis Environmental Remediation Settlement No definition available. 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Number of Solid Waste Management Units No definition available. 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Site Contingency, Environmental Remediation Costs, Period of Recognition No definition available. 
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| X | ||||||||||
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- Definition 
          Site Contingency, Number of Sites No definition available. 
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| X | ||||||||||
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- Definition 
          Total costs accrued as of the balance sheet date for environmental loss contingencies. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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