Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating activities:
Net income	$ 507,673	$ 419,373	$ 307,498
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and intangibles	165,880	161,442	148,179
Amortization of debt premium/discount and issuance costs	1,797	7,852	7,758
Write-off of asset-based revolving credit facility debt issuance costs	21,626	0	0
Excess tax benefit from stock options exercised	(22,985)	(18,587)	(10,215)
Deferred income taxes	54,120	99,257	50,381
Gain on settlement of note receivable	0	(11,639)	0
Share-based compensation programs	20,579	16,973	21,413
Other	8,292	6,893	8,739
Changes in operating assets and liabilities:
Accounts receivable	(21,219)	(21,748)	(9,714)
Inventory	37,740	(110,271)	(339,742)
Accounts payable	383,632	82,574	79,824
Income taxes payable	(8,625)	15,346	6,505
Accrued payroll	(269)	9,939	(16,830)
Accrued benefits and withholdings	1,500	8,930	6,018
Other	(30,750)	37,353	25,386
Net cash provided by operating activities	1,118,991	703,687	285,200
Investing activities:
Purchases of property and equipment	(328,319)	(365,419)	(414,779)
Proceeds from sale of property and equipment	2,715	2,124	4,288
Payments received on notes receivable	5,435	17,364	5,819
Other	516	(5,346)	(5,989)
Net cash used in investing activities	(319,653)	(351,277)	(410,661)
Financing activities:
Proceeds from borrowings on asset-based revolving credit facility	42,400	548,700	664,550
Payments on asset-based revolving credit facility	(398,400)	(871,500)	(599,950)
Proceeds from issuance of long-term debt	795,963	0	0
Payment of debt issuance costs	(9,942)	0	0
Principal payments on debt and capital leases	(1,443)	(108,527)	(13,648)
Repurchases of common stock	(976,632)	0	0
Excess tax benefit from stock options exercised	22,985	18,587	10,215
Net proceeds from issuance of common stock	57,562	63,116	59,508
Other	0	0	420
Net cash used in/provided by financing activities	(467,507)	(349,624)	121,095
Net increase (decrease) in cash and cash equivalents	331,831	2,786	(4,366)
Cash and cash equivalents at beginning of period	29,721	26,935	31,301
Cash and cash equivalents at end of period	361,552	29,721	26,935
Supplemental disclosures of cash flow information:
Income taxes paid	252,769	154,146	130,720
Interest paid, net of capitalized interest	13,350	31,211	36,881
Property and equipment acquired through issuance of capital lease obligations	$ 0	$ 0	$ 8,337