Income Taxes (Provisions) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 27, 2017	Dec. 28, 2016	Dec. 30, 2015	Dec. 28, 2011
Current:
Federal	$ 3,688	$ 4,270	$ 1,622
State and local	2,071	2,316	1,382
Foreign	961	912	873
Deferred:
Federal	10,075	8,225	12,264
State and local	196	619	1,742
Increase (release) of valuation allowance	216	132	(130)	$ (7,200)
Total provisions for income taxes	$ 17,207	$ 16,474	$ 17,753