Stock Repurchase Programs (Details) (USD $)	1 Months Ended		3 Months Ended		9 Months Ended
	Jul. 31, 2014	Jan. 31, 2014	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013	Aug. 31, 2008	Feb. 29, 2008
Equity, Class of Treasury Stock [Line Items]
Shares repurchased			2,154,000	0	3,748,000	0
Total cost of repurchased shares			$ 37,543,000	$ 0	$ 62,575,000	$ 0
Treasury stock repurchase approved	300,000,000	100,000,000
Market value of shares authorized to be repurchased							$ 500,000,000	$ 500,000,000
Remaining number of shares authorized to be repurchased			751,800,000		751,800,000
Approved treasury stock repurchase, term	2 years	2 years