Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 122,153	$ 49,051
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	11,579	9,454
Deferred income tax provision	3,910	2,869
Gain on sale of property and equipment		(822)
Proceeds from insurance settlements	941	703
Stock-based compensation expense	6,894	5,524
(Increase) decrease in, net of effects of acquisitions —
Accounts receivable, net	(13,452)	(27,722)
Inventories, net	157,036	163,372
Prepaid expenses and other assets	(5,329)	(1,799)
(Decrease) Increase in, net of effects of acquisitions —
Accounts payable	(13,316)	5,721
Contract liabilities (customer deposits)	47,110	5,801
Accrued expenses and other liabilities	12,088	9,181
Net cash provided by operating activities	329,614	221,333
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(18,473)	(8,234)
Cash used in acquisition of businesses, net of cash acquired	(111,709)	(1,400)
Purchases of investments	(2,250)
Proceeds from insurance settlements	1,080
Proceeds from sale of property and equipment	247	2,410
Net cash used in investing activities	(131,105)	(7,224)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net payments for short-term borrowings	(183,737)	(165,016)
Proceeds from long-term debt	46,375
Payments for long-term debt	(1,539)
Payments for debt issuance costs	(910)
Contingent acquisition consideration payments	(1,000)	(148)
Purchase of treasury stock	(13,701)	(631)
Net proceeds from issuance of common stock under incentive compensation and employee purchase plans	2,619	1,618
Payments on tax withholdings for equity awards	(2,178)	(1,703)
Net cash used in financing activities	(154,071)	(165,880)
Effect of exchange rate changes on cash	190	179
NET INCREASE IN CASH AND CASH EQUIVALENTS	44,628	48,408
CASH AND CASH EQUIVALENTS, beginning of period	155,493	38,511
CASH AND CASH EQUIVALENTS, end of period	200,121	86,919
Cash paid for:
Interest	3,830	11,663
Income taxes	31,299	4,904
Non-cash items:
Contingent consideration liabilities from acquisitions	$ 8,200
Accounting Standards Update 2016-02 [Member]
Non-cash items:
Initial operating lease right-of-use assets for adoption of ASU 2016-02		42,070
Initial current and noncurrent operating lease liabilities for adoption of ASU 2016-02		$ 43,953