Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement of Cash Flows [Abstract]
Net income (loss)	$ 12,210	$ 8,530
Bad debt expense	(168)	21
Deferred financing cost amortization	46	101
Depreciation and amortization	4,020	2,362
Loss (gain) on sale of assets	(10)	(36)
Non-cash compensation expense	842	931
Deferred income taxes	2,751	2,815
Accounts receivable	6,008	16,699
Inventories	(4,320)	1,683
Costs and estimated earnings in excess of billings	6,101	1,918
Prepaid expenses and other current assets	(2,466)	(6,291)
Other non-current assets	(302)	74
Accounts payable and accrued expenses	(14,764)	(22,772)
Billings in excess of costs and estimated earnings	8,992	4,992
Other non-current liabilities	1,310	(6)
Net cash provided by operating activities	20,250	11,021
Purchases of property and equipment	(1,182)	(1,391)
Proceeds from sale of assets	12	46
Cash paid in conjunction with business combinations	(54,774)
Net cash used in investing activities	(55,944)	(1,345)
Borrowings of debt	25,115	104,189
Repayments of debt	(10,099)	(104,189)
Cash paid for finance leases	(110)
Distribution to noncontrolling interest	0	(457)
Purchase of treasury stock	(695)	(858)
Net cash used in financing activities	14,211	(1,315)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(21,483)	8,361
CASH, CASH EQUIVALENTS, beginning of period		18,934
CASH, CASH EQUIVALENTS, end of period	32,094	27,295
Cash paid for interest	99	273
Cash paid for income taxes (net)	$ 19	$ (707)