Debt (Narrative) (Details)			9 Months Ended				1 Months Ended					1 Months Ended
	May 26, 2012 USD ($)	Mar. 31, 2012 USD ($)	Sep. 29, 2012 Seven Year Four Forty Five Rate [Member]	Sep. 29, 2012 Five Year One Eight Seventy Five Rate [Member]	Sep. 29, 2012 Seven Year Three Twenty Five Rate [Member]	Sep. 29, 2012 Ten Year Four Fifteen Rate [Member]	May 26, 2012 Three Year One One Twenty Five Rate [Member] USD ($)	May 26, 2012 Five Year One Seventy Five Rate [Member] USD ($)	May 26, 2012 Ten Year Three One Twenty Five Rate [Member] USD ($)	May 26, 2012 Two Year Two Ten Rate [Member] CAD	Sep. 29, 2012 Two Year Two Ten Rate [Member] USD ($)	Mar. 31, 2012 Three Hundred Sixty Four Day Term Loan Agreement [Member] USD ($)	May 26, 2012 Three Hundred Sixty Four Day Term Loan Agreement [Member] USD ($)
Debt Instrument [Line Items]
Debt Instrument, Face Amount							$ 350,000,000	$ 400,000,000	$ 700,000,000	300,000,000
Debt instrument term, in years			7 years	5 years	7 years	10 years	3 years	5 years	10 years	2 years
Debt instrument, stated interest rate			4.45%	1.875%	3.25%	4.15%	1.125%	1.75%	3.125%	2.10%
Aggregate net proceeds after debt discount	1,442,000,000										305,000,000
Notional amounts of interest rate swaps		1,600,000,000
Effective interest rate			3.33%	1.20%	2.26%	2.79%
Debt instrument maturity year			2016	2016	2018	2019
Number of days until note maturity												364 days
Credit facility, maximum borrowing capacity												1,000,000,000
Current borrowing amount under credit agreement													$ 0