Earnings Per Share (Details) (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 25, 2011	Sep. 26, 2010	Sep. 25, 2011	Sep. 26, 2010
Earnings Per Share (Thousands of Dollars and Shares Except Per Share Data) [Abstract]
Net earnings-basic (in dollars)	$ 170,990	$ 155,164	$ 246,237	$ 257,738
Effect of dilutive securities:
Interest expense on contingent convertible debentures due 2021, net of tax (in dollars)			0	1,124
Contingent convertible debentures due 2021 (in shares)			0	4,032
Options and other share-based awards (in shares)	2,476	3,516	2,985	3,352
Basic
Adjusted net earnings (basic) (in dollars)	170,990	155,164	246,237	257,738
Average shares outstanding (in shares)	132,448	138,199	135,388	139,773
Equivalent shares (basic) (in shares)	132,448	138,199	135,388	139,773
Net earnings per common share-basic (in dollars per share)	$ 1.29	$ 1.12	$ 1.82	$ 1.84
Diluted
Adjusted net earnings (Diluted) (in dollars)	$ 170,990	$ 155,164	$ 246,237	$ 258,862
Average shares outstanding (in shares)	132,448	138,199	135,388	139,773
Equivalent shares (diluted) (in shares)	134,924	141,715	138,373	147,157
Net earnings per common share-diluted (in dollars per share)	$ 1.27	$ 1.09	$ 1.78	$ 1.76
Options to acquire shares totaling excluded as antidilutive	1,851	931	1,394	1,322