Debt (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				1 Months Ended
	Mar. 30, 2013	Mar. 31, 2012	Feb. 28, 2013	Mar. 30, 2013 3.25% U.S. Dollar Notes due 2018 [Member]	Feb. 28, 2013 Libor plus .23% due February 2015 [Member]	Feb. 28, 2013 2.75% Ten Year U.S. Dollar Notes [Member]	Mar. 30, 2013 4.25% U.S. Dollar Notes [Member]	Mar. 30, 2013 4% Ten Year U.S. Dollar Notes due 2020 [Member]	Mar. 30, 2013 1.75% Five Year U.S. Dollar Notes due 2017 [Member]	Mar. 30, 2013 4.45% Seven Year U.S. Dollar Notes due 2016 [Member]	Mar. 30, 2013 1.875% Five Year U.S. Dollar Notes due 2019 [Member]	Mar. 30, 2013 4.15% Ten Year U.S. Dollar Notes due 2019 [Member]
Debt Instrument [Line Items]
Unrealized gain gain on termination of interest rate fair value hedge				$ 12
Notional amounts of interest rate swaps	650			250
Debt Instrument, Face Amount					250	400
Debt instrument term, in years						10 years		10 years	5 years	7 years	5 years	10 years
Debt instrument maturity year				2018	2015		2013	2020	2017	2016	2016	2019
Debt instrument, stated interest rate				3.25%		2.75%	4.25%	4.00%	1.75%	4.45%	1.875%	4.15%
Debt instrument LIBOR plus rate					LIBOR plus 0.23%
Effective interest rate								2.88%	1.51%	3.27%	1.17%	2.76%
Reductions of long-term debt	749	0					749
Aggregate net proceeds after debt discount and commissions			$ 645