Fair Value Measurements (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Jul. 01, 2011	Dec. 31, 2010
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	$ 844.4	$ 925.7
Other marketable securities	167.5	213.6
Derivative financial instruments - Assets	0.2	0.2
Total Assets	1,012.1	1,139.5
Loan related to other marketable securities	167.5	213.6
Derivative financial instruments - Liabilities	0.3	1.0
Total Liabilities	167.8	214.6
U.S. Government Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	98.0	258.4
Corporate Debt Obligations Guaranteed By FDIC [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	103.0	102.6
Corporate Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	229.2	95.9
Foreign Corporate Debt Obligations Guaranteed By Foreign Governments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	91.6	88.3
Mortgage-Backed Debt Obligations Guaranteed By GNMA [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	99.2	175.1
Certificates Of Deposit Guaranteed By FDIC [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	2.0	3.3
Foreign Government Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	221.4	202.1
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	98.0	258.4
Other marketable securities	167.5	213.6
Total Assets	265.5	472.0
Loan related to other marketable securities	167.5	213.6
Total Liabilities	167.5	213.6
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	98.0	258.4
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	746.4	667.3
Derivative financial instruments - Assets	0.2	0.2
Total Assets	746.6	667.5
Derivative financial instruments - Liabilities	0.3	1.0
Total Liabilities	0.3	1.0
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	103.0	102.6
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	229.2	95.9
Significant Other Observable Inputs (Level 2) [Member] | Foreign Corporate Debt Obligations Guaranteed By Foreign Governments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	91.6	88.3
Significant Other Observable Inputs (Level 2) [Member] | Mortgage-Backed Debt Obligations Guaranteed By GNMA [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments in marketable securities	99.2	175.1
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	2.0	3.3
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	$ 221.4	$ 202.1