Fair Value Measurements (Assets and Liabilities at Fair Value on Recurring Basis) (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Millions, unless otherwise specified	Mar. 24, 2012		Dec. 31, 2011
Total [Member]
Assets:
Cash equivalents			$ 546.0
Interest rate swap	2.9	[1]	4.4	[1]
Total	85.4		641.5
Liabilities:
Total	26.4		26.3
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Cash equivalents			290.0
Interest rate swap	0	[1]	0	[1]
Total	13.8		312.6
Liabilities:
Total	0		0
Significant Observable Inputs (Level 2) [Member]
Assets:
Cash equivalents			256.0
Interest rate swap	2.9	[1]	4.4	[1]
Total	71.6		328.9
Liabilities:
Total	0		0
Significant Unobservable Inputs (Level 3) [Member]
Assets:
Cash equivalents			0
Interest rate swap	0	[1]	0	[1]
Total	0		0
Liabilities:
Contingent consideration	26.4		26.3
Total	26.4		26.3
Prepaid Expenses and Other Current Assets [Member] | Total [Member]
Assets:
Investments	43.7	[1]	52.4	[1]
Prepaid Expenses and Other Current Assets [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Investments	13.8	[1]	22.6	[1]
Prepaid Expenses and Other Current Assets [Member] | Significant Observable Inputs (Level 2) [Member]
Assets:
Investments	29.9	[1]	29.8	[1]
Prepaid Expenses and Other Current Assets [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Investments	0	[1]	0	[1]
Other Assets [Member] | Total [Member]
Assets:
Investments	38.8	[2]	38.7	[2]
Other Assets [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Investments	0	[2]	0	[2]
Other Assets [Member] | Significant Observable Inputs (Level 2) [Member]
Assets:
Investments	38.8	[2]	38.7	[2]
Other Assets [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets:
Investments	0	[2]	0	[2]
Other Accrued Liabilities [Member] | Total [Member]
Liabilities:
Contingent consideration	26.4	[3]	26.3	[3]
Other Accrued Liabilities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Liabilities:
Contingent consideration	0	[3]	0	[3]
Other Accrued Liabilities [Member] | Significant Observable Inputs (Level 2) [Member]
Liabilities:
Contingent consideration	0	[3]	0	[3]
Other Accrued Liabilities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Liabilities:
Contingent consideration	$ 26.4	[3]	$ 26.3	[3]

[1] Included in Prepaid Expenses and Other Current Assets on the balance sheet.

[2] Included in Other Assets on the balance sheet.

[3] Included in Other Accrued Liabilities and Accrued Claims and Other Liabilities on the balance sheet.