Debt (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jul. 01, 2012	Jan. 01, 2012	Jul. 03, 2011
Summary of debt
Maturity	2019
Unamortized discount on Senior Notes	$ (1,456)	$ (1,538)	$ (1,618)
Long-term debt gross	523,301	523,219	523,139
Less: Current portion of debt	120,000	120,000	0
Long-term debt	403,301	403,219	523,139
5.00% Senior Notes 2012 [Member]
Summary of debt
Maturity	2012
Interest Rate	5.00%
Interest Paid	Semi-annually
Long-term debt gross	150,000	150,000	150,000
5.30% Senior Notes 2015 [Member]
Summary of debt
Maturity	2015
Interest Rate	5.30%
Interest Paid	Semi-annually
Long-term debt gross	100,000	100,000	100,000
5.00% Senior Notes 2016 [Member]
Summary of debt
Maturity	2016
Interest Rate	5.00%
Interest Paid	Semi-annually
Long-term debt gross	164,757	164,757	164,757
7.00% Senior Notes 2019 [Member]
Summary of debt
Maturity	2019
Interest Rate	7.00%
Interest Paid	Semi-annually
Long-term debt gross	$ 110,000	$ 110,000	$ 110,000