Fair Value Measurements (Fair Value Measurements - Assets and Liabilities Measured on Recurring and Nonrecurring Basis) (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands		Jun. 30, 2018	Dec. 30, 2017
Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Interest rate swaps	[1]	$ 196	$ 0
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swaps	[1]	861	2,229
Fair Value, Inputs, Level 3 [Member]
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration	[2]	$ 26	$ 25

[1] The Company uses certain external sources in deriving the fair value of the interest rate swaps. The interest rate swaps were valued using observable inputs (e.g., LIBOR yield curves, credit spreads). Valuations of interest rate swaps may fluctuate considerably from period-to-period due to volatility in underlying interest rates, which are driven by market conditions and the duration of the instrument. Credit adjustments could have a significant impact on the valuations due to changes in credit ratings of the Company or its counterparties.

[2] As a result of the Robertex acquisition in 2013, a contingent consideration liability was recorded by the company.