SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year		$ 666	$ 2,391	$ 1,644
Charged to costs and expenses		(130)	(500)	273
Other additions	[1]	201	18	812
Deductions		114	1,243	338
Balance at end of year		623	666	2,391
Environmental Reserves [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year		22,661	23,637	24,635
Charged to costs and expenses		76	1,187	986
Other additions		0	0	0
Deductions		1,070	2,163	1,984
Balance at end of year		21,667	22,661	23,637
Valuation Allowance for Deferred Tax Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year		17,119	22,544	30,394
Charged to costs and expenses		(5)	(5,630)	332
Other additions		536	2,282	0
Deductions		0	2,077	8,182
Balance at end of year		$ 17,650	$ 17,119	$ 22,544

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