Debt (Details 1) (Convertible Senior Notes Due 2015 [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Convertible Senior Notes Due 2015 [Member]
Effective interest rate and components of interest expense of 2015 notes
Debt Instrument, Interest Rate, Effective Percentage	8.10%	8.10%	8.10%
Contractual interest expense	$ 9,157	$ 9,157	$ 9,157
Amortization of debt discount	16,007	14,758	13,665
Total Interest Expense	$ 25,164	$ 23,915	$ 22,822