Annual report pursuant to Section 13 and 15(d)

Environmental Compliance Costs (Details)

v2.4.1.9
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