Consolidated Income Statements - USD ($)	12 Months Ended
	Dec. 25, 2016	Dec. 31, 2015	Dec. 31, 2014
NET SALES	$ 732,677,000	$ 727,946,000	$ 745,447,000
Cost of sales	645,015,000	650,717,000	686,796,000
Restructuring costs (Note 2)	1,458,000	6,012,000	8,429,000
Cost of Goods Sold, Including Restructuring Costs	646,473,000	656,729,000	695,225,000
Gross profit	86,204,000	71,217,000	50,222,000
Selling, general and administrative expenses	31,602,000	34,923,000	32,309,000
INCOME FROM OPERATIONS	54,602,000	36,294,000	17,913,000
Interest income, net	245,000	103,000	1,095,000
Other income (expense), net	(126,000)	(1,114,000)	(3,306,000)
INCOME BEFORE INCOME TAXES	54,721,000	35,283,000	15,702,000
Income tax provision	(13,340,000)	(11,339,000)	(6,899,000)
NET INCOME	$ 41,381,000	$ 23,944,000	$ 8,803,000
EARNINGS PER SHARE - BASIC	$ 1.63	$ 0.90	$ 0.33
EARNINGS PER SHARE - DILUTED	$ 1.62	$ 0.90	$ 0.33