Business Overview And Summary Of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2012
Business Overview And Summary Of Significant Accounting Policies [Abstract]
Approximate number of company owned or leased store locations	2,700
Number of financial institutions where cash and cash equivalents are primarily held	2
Initial lease term of certain distribution centers and manufacturing and store locations, minimum (in months)	1 month
Initial lease term of certain distribution centers and manufacturing and store locations, maximum (in months)	60 months
Initial lease terms of most store locations, minimum (in months)	36 months
Initial lease terms of most store locations, maximum (in months)	48 months
Leasehold improvements on operating leases amortization period (in months)	36 months
Terms of semi-tractor leases (in months)	36 months
Term of non-cancellable pick-up leases (in years)	1 year
Renewal options for non-cancellable pick-up leases, maximum (in months)	72 months
Options vesting and exercisable period, maximum (in years)	8 years
Options termination period after the end of the relevant vesting period (in months)	13 months