Summary of Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 stores states	Dec. 31, 2012	Dec. 31, 2011
Number of stores	4,166
Number of states in which entity operates	42
Accounts receivable due from employees to the Company	$ 1,000,000	$ 2,100,000
Allowance for doubtful vendor receivables	0	0
Replacement cost of inventory	2,380,000,000	2,310,000,000
LIFO inventory value in excess of replacement cost of inventory	21,600,000
Notes receivable from vendors and other third parties	17,200,000	9,500,000
Reserve for uncollectable notes receivables	0	0
Goodwill impairment	0	0
Impairment of long-lived assets	0	0
Self-insurance reserves, current	57,700,000	54,190,000
Instruments qualifying as cash flow or fair value hedges	0	0
Advertising expense, net	78,300,000	74,800,000	73,800,000
Total interest costs capitalized	10,600,000	6,100,000	4,700,000
Deferred debt issuance costs, net of amortization	11,500,000	10,100,000
Deferred debt issuance costs, net of amortization, included in "Other current assets"	1,600,000	1,500,000
Valuation allowance for deferred tax assets	$ 0	$ 0
Minimum [Member]
Note receivable interest rate	0.00%
Maximum [Member]
Note receivable interest rate	10.00%