Convertible Notes (Details 1) (Convertible Senior Notes Due 2015 [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011
Convertible Senior Notes Due 2015 [Member]
Effective interest rate and components of interest expense of 2015 notes
Effective interest rate	8.10%	8.10%	8.10%	8.10%
Contractual interest expense	$ 2,289	$ 2,289	$ 6,867	$ 6,867
Amortization of debt discount	$ 3,737	$ 3,453	$ 10,968	$ 10,166