Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012
Operating activities:
Net income	$ 517,945		$ 452,944
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and intangibles	136,071		132,496
Amortization of debt discount and issuance costs	1,526		1,295
Excess tax benefit from stock options exercised	(25,195)		(30,138)
Deferred income taxes	8,501		18,412
Share-based compensation programs	16,485		16,576
Other	4,635		5,402
Changes in operating assets and liabilities:
Accounts receivable	(24,489)		(22,748)
Inventory	(88,206)		(221,706)
Accounts payable	146,413		584,089
Income taxes payable	18,842		68,622
Other	7,320		27,882
Net cash provided by operating activities	719,848		1,033,126
Investing activities:
Purchases of property and equipment	(299,511)		(217,341)
Proceeds from sale of property and equipment	1,101		2,600
Payments received on notes receivable	3,905		3,115
Net cash used in investing activities	(294,505)		(211,626)
Financing activities:
Proceeds from the issuance of long-term debt	299,976		298,881
Payment of debt issuance costs	(2,967)		(2,229)
Principal payments on capital leases	(207)		(742)
Repurchases of common stock	(687,162)		(1,133,518)
Excess tax benefit from stock options exercised	25,195		30,138
Net proceeds from issuance of common stock	54,702		47,123
Net cash used in financing activities	(310,463)		(760,347)
Net increase in cash and cash equivalents	114,880		61,153
Cash and cash equivalents at beginning of period	248,128	[1]	361,552
Cash and cash equivalents at end of period	363,008		422,705
Supplemental disclosures of cash flow information:
Income taxes paid	271,898		187,750
Interest paid, net of capitalized interest	$ 44,060		$ 35,960

[1] The balance sheet at December 31, 2012, 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.