Other Charges - Operating Expenses Restructuring charges (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)
Restructuring Cost and Reserve [Line Items]
Store Consolidation Plan - Number of Stores Closed	96
Start-up Costs		$ 1.7
Restructuring and Related Cost, Future Lease Obligation	$ 15.0		$ 15.0
Payments for Restructuring	1.0
Gain (Loss) on Disposition of Assets	2.6
Restructuring Charges	$ 18.8
u.s. core [Member]
Restructuring Cost and Reserve [Line Items]
Store Consolidation Plan - Number of Stores Closed	167
Mexico [Member] | Mexico Store Consolidation Plan [Member]
Restructuring Cost and Reserve [Line Items]
Store Consolidation Plan - Number of Stores Closed			14	34
Restructuring Charges		$ 2.8		$ 3.1