Consolidated Condensed Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 24, 2012	Dec. 31, 2011	Mar. 26, 2011
Consolidated Condensed Balance Sheets [Abstract]
Allowances, accounts receivable	$ 12,902	$ 12,688	$ 12,454
Common stock, par value	$ 1	$ 1	$ 1
Common stock, shares authorized	160,000,000	160,000,000	160,000,000
Common stock, shares issued including treasury shares	65,667,720	65,019,406	64,723,233
Treasury stock, shares	17,043,996	16,848,374	15,155,905