Interest Rate Swaps Estimated Amount to be Reclassified into Earnings Next 12 Months (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 31, 2016	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Derivative [Line Items]
Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion		$ 2,240	$ 2,283	$ 0
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	$ 900
Accumulated Other Comprehensive Income (Loss), Net of Tax	1,392	$ 2,763	1,392
Beginning Balance [Member]
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 1,392		$ 1,392	$ 0