Financing Financing (Additional Disclosures) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended		1 Months Ended	3 Months Ended	1 Months Ended
	Sep. 06, 2014	Jun. 14, 2014	Sep. 07, 2013	Sep. 06, 2014	Sep. 07, 2013	Aug. 31, 2014 Senior notes [Member]	Sep. 06, 2014 Mortgages [Member]	Aug. 31, 2014 3.40% Senior Notes due 2016, unsecured [Member] Senior notes [Member]	Aug. 31, 2014 6.35% Senior Notes due 2017, unsecured [Member] Senior notes [Member]
Extinguishment of Debt [Line Items]
Total payments for debt extinguishment						$ 802.7
Debt extinguished							40.8	320.0	400.0
Fixed interest rate of debt								3.40%	6.35%
Principal payments of Senior Notes						720.0
Make-whole premium payments	80.2			82.0	0	80.2
Payment of accrued interest						2.5
Payments for third-party costs related to extinguishment of debt							1.8
Write off of unamortized deferred finance fees	2.4					2.2	0.2
Cash restricted by merger agreement for payment of mortgage		40.0		40.0	0
Release of restricted cash for payment of mortgage	40.0			40.0	0
Loss on extinguishment of debt	$ 84.4		$ 0	$ 84.4	$ 0