Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011
Operating activities:
Net income	$ 452,944		$ 384,685
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and intangibles	132,496		122,741	[1]
Amortization of debt discount and issuance costs	1,295		1,372	[1]
Write-off of asset-based revolving credit facility debt issuance costs	0		21,626	[1]
Excess tax benefit from stock options exercised	(30,138)		(14,705)	[1]
Deferred income taxes	18,412		19,362	[1]
Share-based compensation programs	16,576		15,885	[1]
Other	5,402		7,064	[1]
Changes in operating assets and liabilities:
Accounts receivable	(22,748)		(22,117)	[1]
Inventory	(221,706)		14,082	[1]
Accounts payable	584,089		295,151	[1]
Income taxes payable	68,622		22,004	[1]
Other	27,882		(27,001)	[1]
Net cash provided by operating activities	1,033,126		840,149	[1]
Investing activities:
Purchases of property and equipment	(217,341)		(243,311)	[1]
Proceeds from sale of property and equipment	2,600		750	[1]
Payments received on notes receivable	3,115		4,363	[1]
Other			226	[1]
Net cash used in investing activities	(211,626)		(237,972)	[1]
Financing activities:
Proceeds from borrowings on asset-based revolving credit facility	0		42,400	[1]
Payments on asset-based revolving credit facility	0		(398,400)	[1]
Proceeds from the issuance of long-term debt	298,881		795,963	[1]
Payment of debt issuance costs	(2,229)		(9,942)	[1]
Principal payments on debt and capital leases	(742)		(1,148)	[1]
Repurchases of common stock	(1,133,518)		(840,256)	[1]
Excess tax benefit from stock options exercised	30,138		14,705	[1]
Net proceeds from issuance of common stock	47,123		41,497	[1]
Net cash used in financing activities	(760,347)		(355,181)	[1]
Net increase in cash and cash equivalents	61,153		246,996	[1]
Cash and cash equivalents at beginning of period	361,552	[2]	29,721	[1]
Cash and cash equivalents at end of period	422,705		276,717	[1]
Supplemental disclosures of cash flow information:
Income taxes paid	187,750		185,164	[1]
Interest paid, net of capitalized interest	$ 35,960		$ 14,065	[1]

[1] Certain prior period amounts have been reclassified to conform to current period presentation.

[2] The balance sheet at December 31, 2011, has been derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements.