Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Statement of Cash Flows [Abstract]
Net income (loss)	$ 68,676	$ 40,554	$ 33,478
Bad debt expense		1,864	552
Deferred financing cost amortization	198	152	318
Depreciation and amortization	21,914	12,508	9,557
Loss (gain) on sale of assets	47	0	52
Non-cash compensation	3,522	3,323	2,357
Goodwill impairment expense		6,976	0
Deferred income taxes	11,724	5,122	5,681
Accounts receivable	(55,371)	(25,389)	(35,254)
Inventories	(30,517)	(2,822)	(684)
Costs and estimated earnings in excess of billings	(13,451)	435	1,586
Prepaid expenses and other current assets	(9,226)	(9,355)	(7,171)
Other non-current assets	703	510	(444)
Accounts payable and accrued expenses	30,623	20,122	22,472
Billings in excess of costs and estimated earnings	6,746	13,967	6,683
Other non-current liabilities	1,214	8,774	(459)
Net cash provided by operating activities	37,924	76,741	38,724
Purchases of property and equipment	7,401	4,745	6,300
Proceeds from sale of assets	295	104	502
Cash received (paid) in conjunction with business combinations	92,463	28,952	50
Net cash used in investing activities	(99,569)	(33,593)	(5,748)
Borrowings of debt	1,318,530	592,768	89,261
Repayments of debt	(1,278,204)	(592,756)	(119,508)
Finance lease payment	(648)	(215)	0
Payment for Contingent Consideration Liability, Financing Activities	0	0	(240)
Distribution to noncontrolling interests	(311)	(639)	(240)
Purchase of treasury stock	(7,006)	(7,697)	(9,802)
Issuance of shares	0	34	0
Net cash used in financing activities	31,173	(8,505)	(40,289)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(30,472)	34,643	(7,313)
CASH, CASH EQUIVALENTS and RESTRiCTED CASH, beginning of period	53,577	18,934	26,247
CASH, CASH EQUIVALENTS and RESTRICTED CASH, end of period	23,105	53,577	18,934
Cash paid for interest	738	782	1,743
Cash paid for income taxes (net)	5,062	$ 323	$ 1,370
Payments for Repurchase of Redeemable Noncontrolling Interest	$ (1,188)