Quarterly report pursuant to Section 13 or 15(d)

Fair Value of Financial Instruments (Details Textual)

v2.4.1.9
Fair Value of Financial Instruments (Details Textual) (USD $)
3 Months Ended
Mar. 28, 2015
Mar. 29, 2014
Fair Value of Financial Instruments (Textual) [Abstract]    
Securities held with stated maturities 12 months  
Securities classifies as current assets under caption marketable securities maturities 12 months  
Realized loss on available for sale securities $ 8,000us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet $ 75,000us-gaap_AvailableForSaleSecuritiesGrossRealizedGainLossNet
Other than Temporary Impairment Losses, Investments 0us-gaap_ImpairmentOfInvestments  
Nonrecurring [Member]    
Fair Value of Financial Instruments (Textual) [Abstract]    
Fair value adjustments for assets measured at fair value 0us-gaap_AssetsFairValueAdjustment
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsNonrecurringMember
 
Fair value adjustments for liabilities measured at fair value 0us-gaap_LiabilitiesFairValueAdjustment
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsNonrecurringMember
 
Phantom stock units [Member]    
Fair Value of Financial Instruments (Textual) [Abstract]    
Phantom stock units, Vesting Period 3 years  
Deferred director stock units and phantom stock units liability [Member]    
Fair Value of Financial Instruments (Textual) [Abstract]    
Recognized expense related to deferred director stock units and phantom stock units liability $ 11,000snhy_FairValueLiabilityRecordedForShareBasedAwardsRelatedExpense
/ us-gaap_IncomeStatementLocationAxis
= snhy_DeferredDirectorStockUnitsAndPhantomStockUnitsLiabilityMember
$ 12,000snhy_FairValueLiabilityRecordedForShareBasedAwardsRelatedExpense
/ us-gaap_IncomeStatementLocationAxis
= snhy_DeferredDirectorStockUnitsAndPhantomStockUnitsLiabilityMember