Fair Value Measurements (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Mar. 30, 2012	Dec. 30, 2011
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	$ 821.2	$ 843.9
Other marketable securities	223.3	190.9
Derivative financial instruments	0.4	0.2
Total Assets	1,044.9	1,035.0
Loan related to other marketable securities	223.3	190.9
Derivative financial instruments	0.2	0.2
Total Liabilities	223.5	191.1
U.S. Government Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	185.9	195.7
Corporate Debt Obligations Guaranteed By FDIC [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	50.6	66.8
Corporate Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	194.7	201.5
Foreign Corporate Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	66.4	64.2
Mortgaged Backed Debt Obligations Guaranteed By GNMA [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	84.0	91.2
Certificates Of Deposit Guaranteed By FDIC [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	1.5	1.5
Foreign Government Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	238.1	223.0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	185.9	195.7
Other marketable securities	223.3	190.9
Derivative financial instruments
Total Assets	409.2	386.6
Loan related to other marketable securities	223.3	190.9
Derivative financial instruments
Total Liabilities	223.3	190.9
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | U.S. Government Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	185.9	195.7
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Corporate Debt Obligations Guaranteed By FDIC [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Corporate Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Foreign Corporate Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Mortgaged Backed Debt Obligations Guaranteed By GNMA [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Certificates Of Deposit Guaranteed By FDIC [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Foreign Government Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	635.3	648.2
Other marketable securities
Derivative financial instruments	0.4	0.2
Total Assets	635.7	648.4
Loan related to other marketable securities
Derivative financial instruments	0.2	0.2
Total Liabilities	0.2	0.2
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Significant Other Observable Inputs (Level 2) [Member] | Corporate Debt Obligations Guaranteed By FDIC [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	50.6	66.8
Significant Other Observable Inputs (Level 2) [Member] | Corporate Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	194.7	201.5
Significant Other Observable Inputs (Level 2) [Member] | Foreign Corporate Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	66.4	64.2
Significant Other Observable Inputs (Level 2) [Member] | Mortgaged Backed Debt Obligations Guaranteed By GNMA [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	84.0	91.2
Significant Other Observable Inputs (Level 2) [Member] | Certificates Of Deposit Guaranteed By FDIC [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	1.5	1.5
Significant Other Observable Inputs (Level 2) [Member] | Foreign Government Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	238.1	223.0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Other marketable securities
Derivative financial instruments
Total Assets
Loan related to other marketable securities
Derivative financial instruments
Total Liabilities
Significant Unobservable Inputs (Level 3) [Member] | U.S. Government Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Significant Unobservable Inputs (Level 3) [Member] | Corporate Debt Obligations Guaranteed By FDIC [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Significant Unobservable Inputs (Level 3) [Member] | Corporate Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Significant Unobservable Inputs (Level 3) [Member] | Foreign Corporate Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Significant Unobservable Inputs (Level 3) [Member] | Mortgaged Backed Debt Obligations Guaranteed By GNMA [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Significant Unobservable Inputs (Level 3) [Member] | Certificates Of Deposit Guaranteed By FDIC [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities
Significant Unobservable Inputs (Level 3) [Member] | Foreign Government Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities