Stock Repurchase Programs (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011
Repurchase of common shares
Remaining Authorization	$ 814,389
Share repurchased and total cost of repurchased shares
Shares repurchased		6,493
Total cost of repurchased shares		39,997
February 2008 [Member]
Repurchase of common shares
Amount	500,000
Remaining Authorization	314,389
August 2008 [Member]
Repurchase of common shares
Amount	500,000
Remaining Authorization	$ 500,000