Convertible Notes (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011
Remaining consideration remitted allocated to debt component of notes
Principal amount repurchased		$ 205,539
Amount allocated to
Extinguishment of liability component		186,746
Extinguishment of equity component		5,618
Total cash paid for repurchase	150,000	192,364
Notes Due 2011 [Member]
Remaining consideration remitted allocated to debt component of notes
Principal amount repurchased		100,000
Amount allocated to
Extinguishment of liability component		95,865
Extinguishment of equity component		2,285
Total cash paid for repurchase		98,150
Notes Due 2013 [Member]
Remaining consideration remitted allocated to debt component of notes
Principal amount repurchased		105,539
Amount allocated to
Extinguishment of liability component		90,881
Extinguishment of equity component		3,333
Total cash paid for repurchase		$ 94,214