Condensed Consolidated Statements of Cash Flows (USD $)	6 Months Ended
	Jun. 24, 2012	Jun. 26, 2011
NET CASH PROVIDED BY OPERATING ACTIVITIES	$ 34,564,000	$ 9,316,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to property, plant and equipment	(8,661,000)	(9,480,000)
Proceeds from life insurance policy	1,726,000	0
Proceeds from sales and maturities of investments	3,142,000	20,757,000
Purchase of investments	(2,808,000)	(3,973,000)
Collection of amounts receivable from sale of unconsolidated affiliate	0	2,867,000
Loan to unconsolidated affiliate	0	(450,000)
Premiums paid for life insurance	0	(217,000)
Other	240,000	74,000
NET CASH USED IN INVESTING ACTIVITIES	(6,361,000)	9,578,000
CASH FLOWS FROM FINANCING ACTIVITIES:
Cash dividends paid	(8,703,000)	(8,665,000)
Proceeds from exercise of stock options	417,000	4,341,000
Excess tax benefits from exercise of stock options	0	273,000
NET CASH USED IN FINANCING ACTIVITIES	(8,286,000)	(4,051,000)
Effect of exchange rate changes on cash	(218,000)	0
Net increase in cash and cash equivalents	19,699,000	14,843,000
Cash and cash equivalents at the beginning of the period	187,795,000	129,631,000
Cash and cash equivalents at the end of period	$ 207,494,000	$ 144,474,000