Quarterly report pursuant to Section 13 or 15(d)

Fair Value of Financial Instruments (Details Textual)

v3.2.0.727
Fair Value of Financial Instruments (Details Textual) - USD ($)
3 Months Ended 6 Months Ended
Jun. 27, 2015
Jun. 27, 2015
Jun. 28, 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   $ 117,000 $ 160,000
Other than Temporary Impairment Losses, Investments $ 0    
Nonrecurring [Member]      
Fair Value of Financial Instruments (Textual) [Abstract]      
Fair value adjustments for assets measured at fair value   0  
Fair value adjustments for liabilities measured at fair value   $ 0  
Phantom Share Units (PSUs) [Member]      
Fair Value of Financial Instruments (Textual) [Abstract]      
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   3 years  
Recognized expense related to deferred director stock units and phantom stock units liability   $ 17,000 $ 21,000