Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014
Operating activities:
Net income	$ 712,640		$ 596,504
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and intangibles	158,065		143,515
Amortization of debt discount and issuance costs	1,578		1,563
Excess tax benefit from share-based compensation	(50,759)		(32,296)
Deferred income taxes	(22,780)		(18,108)
Share-based compensation programs	16,656		17,424
Other	4,194		3,801
Changes in operating assets and liabilities:
Accounts receivable	(24,511)		(26,167)
Inventory	(52,024)		(142,880)
Accounts payable	208,959		352,533
Income taxes payable	85,428		51,043
Other	25,276		36,022
Net cash provided by operating activities	1,062,722		982,954
Investing activities:
Purchases of property and equipment	(296,474)		(317,157)
Proceeds from sale of property and equipment	2,197		2,304
Payments received on notes receivable	3,028		2,770
Net cash used in investing activities	(291,249)		(312,083)
Financing activities:
Principal payments on capital leases	(25)		(54)
Repurchases of common stock	(849,202)		(687,154)
Excess tax benefit from share-based compensation	50,759		32,296
Net proceeds from issuance of common stock	53,351		51,006
Net cash used in financing activities	(745,117)		(603,906)
Net increase in cash and cash equivalents	26,356		66,965
Cash and cash equivalents at beginning of the period	250,560	[1]	231,318
Cash and cash equivalents at end of the period	276,916		298,283
Supplemental disclosures of cash flow information:
Income taxes paid	342,920		308,029
Interest paid, net of capitalized interest	$ 51,003		$ 47,173

[1] The balance sheet at December 31, 2014, has been derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by United States generally accepted accounting principles for complete financial statements.