Employee Benefit Plans Employee Benefit Plans Narrative 3 (Details) $ in Thousands	12 Months Ended
	Dec. 30, 2017 USD ($) plan	Dec. 31, 2016 USD ($)	Jan. 02, 2016 USD ($)
Employee Benefit Plans [Abstract]
Number of Multiemployer Plans, Certified Red Zone	6
Number Of Multiemployer Plans, Withdrawal Obligation Could Be Material	2
Number of Multiemployer Plans, Certified Yellow Zone	1
Contributions | $	$ 3,472	$ 3,373	$ 3,231
Multiemployer Plans, Withdrawal Obligation | $	$ 1,700