Debt (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended	12 Months Ended	1 Months Ended			6 Months Ended	12 Months Ended			6 Months Ended
	Jun. 29, 2014 Line of Credit, Maturing January 8, 2019 [Member]	Jun. 29, 2014 Line of Credit, Maturing January 8, 2019 [Member]	Dec. 29, 2013 Line of Credit, Maturing December 16, 2016 [Member]	Oct. 25, 2011 2021 Notes [Member]	Jun. 29, 2014 2021 Notes [Member]	Dec. 29, 2013 2021 Notes [Member]	Jun. 29, 2014 2021 Notes [Member] Treasury Rate [Member]	Dec. 29, 2013 Financing Lease Obligations [Member]	Jun. 29, 2014 Financing Lease Obligations [Member]	Sep. 30, 2012 Financing Lease Obligations [Member]	Jun. 29, 2014 Unsecured Revolving Credit Facility [Member] Base Rate Option Two [Member]	Jun. 29, 2014 Unsecured Revolving Credit Facility [Member] Eurocurrency Rate [Member]	Jun. 29, 2014 Unsecured Revolving Credit Facility [Member] Line of Credit, Maturing January 8, 2019 [Member]	Jun. 29, 2014 Unsecured Revolving Credit Facility [Member] Line of Credit, Maturing January 8, 2019 [Member] Base Rate Option Three [Member]	Jun. 29, 2014 Unsecured Revolving Credit Facility [Member] Line of Credit, Maturing January 8, 2019 [Member] Base Rate Option Two [Member]	Jun. 29, 2014 Unsecured Revolving Credit Facility [Member] Line of Credit, Maturing January 8, 2019 [Member] Eurocurrency Rate [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 700.0	$ 700.0	$ 700.0
Unsecured revolving credit facility, expiry date		Jan. 08, 2019	Dec. 16, 2016
Letters of credit issued and outstanding	12.2	12.2
Line of Credit Facility, Remaining Borrowing Capacity	329.8	329.8
Interest rate terms under amended senior unsecured revolving credit facility													The interest rates under the senior unsecured revolving credit facility are based on the Eurocurrency rate or the base rate at the time of borrowing, plus a margin. The base rate is the higher of (i) the rate of interest in effect for such day as publicly announced from time to time by JP Morgan Chase Bank, N.A. as its "prime rate," (ii) the Federal Funds rate plus 50 basis points or (iii) one-month Libor plus 1.00%.
Weighted average interest rates under amended senior unsecured revolving credit facility													The Eurocurrency margin as of June 29, 2014 was 108 basis points. The weighted average Eurocurrency interest rate as of June 29, 2014 was 0.18%, resulting in a weighted average effective Eurocurrency rate, including the margin, of 1.26%.
Description of variable rate basis											Federal Funds	Eurocurrency
Basis spread on variable rate							0.45%							1.00%	0.50%	1.08%
Weighted average Eurocurrency interest rate																0.18%
Weighted average effective Eurocurrency rate, including the margin																1.26%
Aggregate borrowings under the amended facility	358.0	358.0	397.0
Debt Issuance Cost	1.8
Debt Instrument, Interest Rate, Stated Percentage				5.00%
Unsecured senior notes, face value				500.0	500.0
Gross proceeds from the issuance of debt instrument				496.9
Senior unsecured notes issuance as percentage of principal amount				99.372%
Debt Instrument, Unamortized Discount				3.1	2.5	2.6
Long-term Debt, Gross					497.5	497.4
Debt instrument maturity date				Nov. 25, 2021
Percentage of redemption of senior notes on or after August 15, 2021				100.00%
Percentage of redemption upon a change of control and a contemporaneous downgrade of the Notes				101.00%
Initial Fair Value of Other Long-term Debt Related to Financing Lease Obligations										29.3
Other Long-term Debt								40.3	39.8
Other Long-term Debt, Current								2.6	1.1
Other Long-term Debt, Noncurrent								37.7	38.7
Additional Financing Lease Obligations, funded by lessors								$ 11.5