Debt And Bank Credit Facilities (Narrative) (Details) (USD $)	0 Months Ended			6 Months Ended		0 Months Ended
	Jun. 30, 2011	Jul. 02, 2011	Jan. 01, 2011	Jul. 02, 2011 Floating Rate Series 2007A Senior Notes, Tranche A, [Member]	Jul. 02, 2011 Floating Rate Series 2007A Senior Notes, Tranche B, [Member]	Jun. 16, 2008 Term Loan [Member]
Senior Notes		$ 250,000,000	$ 250,000,000	$ 150,000,000	$ 100,000,000
Debt instrument maturity date				August 23, 2014	August 23, 2017	June 2013
Principal amount of debt						165,000,000
Revolving credit facility, maturity date	June 2016
Interest rate based on margin over London Inter-Bank Offered Rate				0.90%	0.90%	0.90%
Revolving credit facility	500,000,000
Other notes payable amount outstanding		$ 27,300,000
Weighted average interest rate of other notes payable		6.00%