Debt, Commitments And Contingencies (Narrative) (Details) (USD $)			3 Months Ended					3 Months Ended					0 Months Ended					3 Months Ended			3 Months Ended
	Mar. 30, 2012	Dec. 30, 2011	Mar. 30, 2012 2011 Credit Facility [Member]	May 06, 2011 2011 Credit Facility [Member]	Mar. 30, 2012 Revolving Credit Facility [Member]	Dec. 30, 2011 Revolving Credit Facility [Member]	May 06, 2011 Revolving Credit Facility [Member]	Mar. 30, 2012 Promissory Notes And Other Debt [Member]	Dec. 30, 2011 Promissory Notes And Other Debt [Member]	Mar. 30, 2012 Term Loan [Member]	Dec. 30, 2011 Term Loan [Member]	May 06, 2011 Term Loan [Member]	Jul. 14, 2011 Uncommitted Facility [Member]	Mar. 30, 2012 Uncommitted Facility [Member]	Jan. 27, 2012 Uncommitted Facility [Member]	Mar. 30, 2012 Long-term Debt [Member]	Dec. 30, 2011 Long-term Debt [Member]	Mar. 30, 2012 Minimum [Member]	Mar. 30, 2012 Minimum [Member] Reserve-Adjusted Rate [Member]	Mar. 30, 2012 Minimum [Member] Base Rate Plus [Member]	Mar. 30, 2012 Maximum [Member]	Mar. 30, 2012 Maximum [Member] Reserve-Adjusted Rate [Member]	Mar. 30, 2012 Maximum [Member] Base Rate Plus [Member]	Mar. 30, 2012 Notes Payable, Primarily To Noncontrolling Interest [Member]	Dec. 30, 2011 Notes Payable, Primarily To Noncontrolling Interest [Member]
Debt Instrument [Line Items]
Unsecured revolving credit agreement				$ 1,100,000,000
Increase in available revolving credit line				300,000,000											75,000,000
Aggregate availability of revolving credit line							700,000,000
Term loan credit facility maximum borrowing amount												400,000,000
Line of credit facility uncommitted fee amount													50,000,000
Total debt	623,133,000	564,436,000	175,000,000		241,000,000	177,300,000		2,133,000	2,136,000	380,000,000	385,000,000			66,000,000
Total debt								2,100,000	2,100,000
Non-current portion of long-term debt	535,204,000	498,518,000			175,000,000					360,000,000						200,000	200,000
Credit facility commitment fee, percentage																		0.20%			0.40%
Unsecured revolving credit facility, initiation date			May 6, 2011
Unsecured revolving credit facility, expiration date			May 6, 2016
Amortization of credit facility percentage year one			5.00%
Amortization of credit facility percentage year two			5.00%
Amortization of credit facility percentage year three			10.00%
Amortization of credit facility percentage year four			10.00%
Amortization of credit facility percentage year five			70.00%
Credit facility interest rate in addition to specific base rates														1.00%					1.25%	0.25%		2.25%	1.25%
Maximum leverage and minimum interest coverage ratio			3.5
Outstanding notes payable																								1,700,000	1,700,000
Interest rate on notes								6.00%
Callable notification, months								6
Acquisition-related earn-outs as current liabilities	5,500,000
Acquisition-related holdbacks as non-current liabilities	5,600,000
Unconditional purchase obligations	94,800,000
Additional potential earn-out cash payments	$ 7,400,000