SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 27, 2014		Dec. 28, 2013		Dec. 29, 2012
Allowance for Doubtful Accounts [Member]
Valuation Allowances and Reserves (Roll Forward)
Balance	$ 2,391		$ 1,644		$ 1,564
Charged to costs and expenses	(500)		273		867
Other additions	18	[1]	812	[1]	109	[1]
Deductions	1,243		338		896
Balance	666		2,391		1,644
Environmental Reserves [Member]
Valuation Allowances and Reserves (Roll Forward)
Balance	23,637		24,635		22,892
Charged to costs and expenses	1,187		986		3,056
Other additions	0		0		0
Deductions	2,163		1,984		1,313
Balance	22,661		23,637		24,635
Valuation Allowance of Deferred Tax Assets [Member]
Valuation Allowances and Reserves (Roll Forward)
Balance	22,544		30,394		29,705
Charged to costs and expenses	(5,630)		332		(1,224)
Other additions	2,282		0		1,913
Deductions	2,077		8,182		0
Balance	$ 17,119		$ 22,544		$ 30,394

[1] Other consists primarily of bad debt recoveries as well as the effect of fluctuating foreign currency exchange rates in all years presented.