Annual report pursuant to Section 13 and 15(d)

Fair Value of Financial Instruments (Details)

v3.8.0.1
Fair Value of Financial Instruments (Details) - Recurring [Member] - USD ($)
$ in Thousands
Dec. 30, 2017
Dec. 31, 2016
Liabilities    
Liabilities measured at fair value $ 33,882  
Assets    
Assets measured at fair value, Adjusted cost   $ 7,446
Assets measured at fair value, Unrealized gains   40
Assets measured at fair value, Unrealized losses   (661)
Asset measured at, fair value   6,825
Contingent Consideration [Member]    
Liabilities    
Liabilities measured at fair value 33,882  
Level 1 [Member]    
Assets    
Assets measured at fair value, Adjusted cost   1,483
Assets measured at fair value, Unrealized gains   31
Assets measured at fair value, Unrealized losses   (159)
Asset measured at, fair value   1,355
Level 1 [Member] | Equity securities [Member]    
Assets    
Assets measured at fair value, Adjusted cost   0
Assets measured at fair value, Unrealized gains   31
Assets measured at fair value, Unrealized losses   0
Asset measured at, fair value   31
Level 1 [Member] | Mutual funds [Member]    
Assets    
Assets measured at fair value, Adjusted cost   1,483
Assets measured at fair value, Unrealized gains   0
Assets measured at fair value, Unrealized losses   (159)
Asset measured at, fair value   1,324
Level 2 [Member]    
Assets    
Assets measured at fair value, Adjusted cost   5,963
Assets measured at fair value, Unrealized gains   9
Assets measured at fair value, Unrealized losses   (502)
Asset measured at, fair value   5,470
Level 2 [Member] | Corporate fixed income [Member]    
Assets    
Assets measured at fair value, Adjusted cost   4,288
Assets measured at fair value, Unrealized gains   9
Assets measured at fair value, Unrealized losses   (408)
Asset measured at, fair value   3,889
Level 2 [Member] | Municipal bonds [Member]    
Assets    
Assets measured at fair value, Adjusted cost   1,675
Assets measured at fair value, Unrealized gains   0
Assets measured at fair value, Unrealized losses   (94)
Asset measured at, fair value   1,581
Level 3 [Member]    
Liabilities    
Liabilities Measured at Fair Value Adjusted Cost   0
Liabilities measured at fair value, Unrealized gains   0
Liabilities measured at fair value, Unrealized losses   0
Liabilities measured at fair value 33,882 35,077
Level 3 [Member] | Contingent Consideration [Member]    
Liabilities    
Liabilities Measured at Fair Value Adjusted Cost   0
Liabilities measured at fair value, Unrealized gains   0
Liabilities measured at fair value, Unrealized losses   0
Liabilities measured at fair value $ 33,882 $ 35,077