Quarterly Financial Data (unaudited) (Dividends and stock prices) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Oct. 01, 2011	Jul. 02, 2011	Apr. 02, 2011	Jan. 01, 2011	Oct. 02, 2010	Jul. 03, 2010	Apr. 03, 2010	Dec. 31, 2011	Jan. 01, 2011	Jan. 02, 2010
Quarterly Financial Data [Abstract]
Dividend per share	$ 0.4300	$ 0.4300	$ 0.4050	$ 0.4050	$ 0.4050	$ 0.4050	$ 0.3750	$ 0.3750	$ 1.670	$ 1.560	$ 1.430
High stock price	$ 55.30	$ 56.39	$ 57.70	$ 55.41	$ 51.62	$ 52.58	$ 56.00	$ 55.45	$ 55.30	$ 51.62
Low stock price	$ 48.10	$ 50.38	$ 53.45	$ 49.99	$ 48.51	$ 47.28	$ 49.75	$ 51.70	$ 48.10	$ 48.51