Debt Table (Details) (USD $)						3 Months Ended		9 Months Ended						3 Months Ended			9 Months Ended
	Sep. 24, 2011		Dec. 25, 2010		Jun. 30, 2007	Sep. 24, 2011 Senior Notes [Member]	Sep. 25, 2010 Senior Notes [Member]	Sep. 24, 2011 Senior Notes [Member]	Sep. 25, 2010 Senior Notes [Member]	Sep. 24, 2011 Senior Notes [Member] $850 million 6.375% Senior Notes due 2012	Dec. 25, 2010 Senior Notes [Member] $850 million 6.375% Senior Notes due 2012	Sep. 24, 2011 Senior Notes [Member] Canadian dollar ("CAD") 900 million 5.0% notes due 2015	Dec. 25, 2010 Senior Notes [Member] Canadian dollar ("CAD") 900 million 5.0% notes due 2015	Sep. 24, 2011 Senior Notes [Member] $575 million 2.5% convertible Senior Notes due 2013		Sep. 25, 2010 Senior Notes [Member] $575 million 2.5% convertible Senior Notes due 2013	Sep. 24, 2011 Senior Notes [Member] $575 million 2.5% convertible Senior Notes due 2013		Sep. 25, 2010 Senior Notes [Member] $575 million 2.5% convertible Senior Notes due 2013	Jun. 25, 2011 Senior Notes [Member] $575 million 2.5% convertible Senior Notes due 2013	Dec. 25, 2010 Senior Notes [Member] $575 million 2.5% convertible Senior Notes due 2013		Sep. 24, 2011 Senior Notes [Member] CAD 500 million 3.95% Series A notes due 2017	Dec. 25, 2010 Senior Notes [Member] CAD 500 million 3.95% Series A notes due 2017	Dec. 25, 2010 Other Debt Obligations [Member]	Sep. 24, 2011 Other Debt Obligations [Member] $575 million 2.5% convertible Senior Notes due 2013
Debt Instrument [Line Items]
Total long-term debt (including current portion) before unamortized discounts and other										$ 44,600,000	$ 44,600,000	$ 875,400,000	$ 892,600,000	$ 575,000,000	[1],[2]		$ 575,000,000	[1],[2]			$ 575,000,000	[1],[2]	$ 486,300,000	$ 495,900,000
Less: unamortized debt discounts and other	(35,200,000)	[1]	(48,500,000)	[1]
Total long-term debt (including current portion)	1,946,100,000		1,959,600,000
Less: current portion of long-term debt	(44,800,000)		0
Total long-term debt	1,901,300,000		1,959,600,000
Total fair value	2,137,700,000		2,137,600,000
Debt Instruments [Abstract]
Debt Instrument, Principal Amount, Per Share																				1,000
Debt Instrument, Convertible Conversion Price Per Share														$ 54.76			$ 54.76			$ 53.40
Percentage of Premium over Stock Price of Convertible Debt																				25.00%
Debt Instrument, Convertible Number of Equity Instruments, Ratio														18.263			18.263			18.7251
Interest Expense Debt Amortization						4,400,000	4,200,000	13,100,000	12,600,000
Debt Instrument, Interest Rate, Stated Percentage										6.375%		5.00%		2.50%		2.50%	2.50%		2.50%				3.95%
Interest Expense, Debt														3,600,000		3,600,000	10,800,000		10,800,000
Debt Instruments, Interest Rate Effective Percentage														5.86%		5.95%	5.87%		5.95%
Debt Instrument, Convertible, Carrying Amount of Equity Component														103,900,000			103,900,000				103,900,000
Debt Instrument, Convertible Carrying Amount of the Equity Component, Net of Tax														64,200,000			64,200,000				64,200,000
Debt Instrument, Unamortized Discount														33,200,000			33,200,000				46,300,000				2,000,000	2,000,000
Debt face amount					575,000,000					850,000,000		900,000,000								575,000,000			500,000,000
Noncash Interest Expense Due to Amortization of Unamortized Debt Discount in Future Periods Convertible Debt Estimated Range Low																	17,000,000
Noncash Interest Expense Due to Amortization of Unamortized Debt Discount in Future Periods Convertible Debt Estimated Range High																	18,000,000
Debt Instrument Unamortized Discount on Additional Debts														$ 33,200,000			$ 33,200,000				$ 46,300,000				$ 2,000,000	$ 2,000,000

[1] During the third quarters of 2011 and 2010, we incurred additional non-cash interest expense of $4.4 million and $4.2 million, respectively. For the first three quarters of 2011 and 2010, the amounts were $13.1 million and $12.6 million, respectively. We also incurred interest expense related to the 2.5% convertible coupon rate of $3.6 million for both the third quarters of 2011 and 2010. For the first three quarters of 2011 and 2010, the amount was $10.8 million for both periods. The combination of non-cash and cash interest resulted in an effective interest rate of 5.86% and 5.95% for the third quarters of 2011 and 2010, respectively. The effective interest rates for the first three quarters of 2011 and 2010 were 5.87% and 5.95%, respectively. As of September 24, 2011, and December 25, 2010, paid in capital in the equity section of our balance sheet includes $103.9 million, ($64.2 million net of tax), representing the equity component of the convertible debt. Further, as of September 24, 2011, and December 25, 2010, $33.2 million and $46.3 million, respectively, of the unamortized debt discount and other balance relates to our $575 million convertible debt. We expect the unamortized discount to continue to amortize through 2013, resulting in non-cash interest expense of approximately $17 million to $18 million annually, thereby increasing the carrying value of the convertible debt to its $575 million face value at maturity in July 2013. The remaining $2.0 million as of September 24, 2011, and December 25, 2010, relates to unamortized debt premiums, discounts, and other on the additional debt balances.

[2] The original conversion price for each $1,000 aggregate principal amount of notes was $54.76 per share of our Class B common stock, which represented a 25% premium above the stock price on the day of issuance of the notes and corresponded to the initial conversion ratio of 18.263 shares per each $1,000 aggregate principal amount of notes. The conversion ratio and conversion price are subject to adjustments for certain events and provisions, as defined in the indenture. As of June 2011, our conversion price and ratio are $53.40 and 18.7251 shares, respectively. Currently, the convertible debt's if-converted value does not exceed the principal.