CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Cash Flows From Operating Activities:
Net income	$ 62,849	$ 53,477	$ 42,580
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,038	9,062	6,284
Amortization of debt issuance costs	38	41	65
Stock-based compensation	3,553	2,157	831
Deferred income taxes	1,410	1,182	597
Earnings of equity method investees	(337)	(318)	(268)
Excess tax benefit of exercise of common stock options and restricted stock vesting	(1,323)	(895)	(2,714)
Loss on disposal of property and equipment	111	32
Other	(280)	(206)	(76)
Changes in operating assets and liabilities (net of effects of business acquisitions):
Receivables	(15,173)	(48,879)	(23,021)
Inventories	(72,864)	(52,831)	8,553
Prepaid expenses and other assets	3,135	(1,118)	3,398
Accounts payable	63,403	50,018	(5,150)
Accrued expenses	2,889	2,516	1,349
Net cash provided by operating activities	57,449	14,238	32,428
Cash Flows From Investing Activities:
Business acquisitions, net of cash acquired	(17,107)	(51,718)	(9,000)
Purchases of property and equipment	(10,780)	(7,597)	(12,516)
Proceeds from sales of property and equipment	189	96
Other	(430)	(646)	(3,993)
Net cash used in investing activities	(28,128)	(59,865)	(25,509)
Cash Flows From Financing Activities:
Borrowings on credit facilities	673,249	539,071	249,978
Payments on credit facilities	(702,271)	(494,186)	(257,166)
Proceeds from issuance of common stock	651	562	412
Proceeds from exercise of stock options	108	154	98
Excess tax benefit of exercise of common stock options and restricted stock vesting	1,323	895	2,714
Tax withholdings on net settlements of share-based awards	(1,855)
Debt issuance costs		(111)
Payment on long-term debt and capital lease obligations	(312)	(986)	(3,327)
Net cash (used in)/provided by financing activities	(29,107)	45,399	(7,291)
Effect of Exchange Rate on Cash and Cash Equivalents	225	136	67
Net Increase (Decrease) in Cash and Cash Equivalents	439	(92)	(305)
Cash and Cash Equivalents at Beginning of Period	514	606	911
Cash and Cash Equivalents at End of Period	$ 953	$ 514	$ 606