Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2012

Financial Instruments (Thousands of Dollars) [Abstract]

Schedule of long-term debt instruments

	Sept. 30, 2012		Sept. 25, 2011		Dec. 25, 2011
	--------------------		--------------------		----------------------------
	Carrying Cost	Fair Value	Carrying Cost	Fair Value	Carrying Cost	Fair Value
	-------	------	-------	------	-------	------
6.35% Notes Due 2040	$   500,000	599,300	500,000	547,200	500,000	540,850
6.125% Notes Due 2014	439,011	459,680	445,176	467,245	440,977	462,868
6.30% Notes Due 2017	350,000	409,325	350,000	402,780	350,000	400,400
6.60% Debentures    Due 2028	109,895	127,478	109,895	120,775	109,895	120,148
	-------------	-------------	-------------	-----------	-------------	-----------
Total long-term debt	$1,398,906	1,595,783	1,405,071	1,538,000	1,400,872	1,524,266
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