Long-Term Debt and Capital Leases (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 01, 2013	Feb. 28, 2013	Dec. 30, 2012	Mar. 31, 2013 Letter of Credit [Member]	Mar. 31, 2013 Term Loans due October 2015, weighted average rate of 1.59% [Member]	Dec. 30, 2012 Term Loans due October 2015, weighted average rate of 1.59% [Member]	Oct. 22, 2012 Term Loans due October 2015, weighted average rate of 1.59% [Member]
Long-Term Debt and Capital Leases (Additional Textual) [Abstract]
Maximum borrowing capacity	$ 750.0	$ 750.0	$ 550.0
Long-term debt	683.2			543.4		200.0	200.0	200.0
Maximum credit facility term drawn to date	3 months
Incremental line of credit for standby letters of credit	2.0
Letter of credit, outstanding					14.6
Long-Term Debt and Capital Leases (Textual) [Abstract]
Credit agreement provides for facility fees, minimum	0.125%
Credit agreement provides for facility fees, maximum	0.30%
Available borrowings capacity under letters of credit	516.5
Uncommitted credit line permits extensions for standby letters of credit	5.0
Total capital leases	13.2			14.3
Capital leases, current	$ 1.4			$ 1.5