Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Statement of Financial Position [Abstract]
Cash and cash equivalents	$ 7,826	$ 23,105
Accounts receivable	294,789	286,707
Accounts and Other Receivables, Net, Current	45,741	41,341
Inventories	73,766	68,573
Costs and estimated earnings in excess of billings	52,529	43,389
Prepaid expenses and other current assets	21,838	21,065
Total current assets	496,489	484,180
Property and equipment, net	45,264	35,454
Goodwill	92,395	92,395
Intangible assets, net	82,093	85,619
Deferred tax assets	16,815	19,009
Operating right of use assets	42,531	42,916
Other non-current assets	9,641	7,049
Total assets	785,228	766,622
Accounts payable and accrued expenses	232,548	249,114
Billings in excess of costs and estimated earnings	66,242	62,486
Total current liabilities	298,790	311,600
Long-term debt	67,827	39,746
Operating long-term lease liabilities	27,520	28,649
Other non-current liabilities	10,561	16,080
Total liabilities	404,698	396,075
Noncontrolling interest	24,070	24,594
Preferred stock, value	0	0
Common stock, value	220	220
Treasury stock, value	(30,460)	(29,300)
Additional paid-in capital	199,162	201,899
Retained earnings	187,538	173,134
Total stockholders' equity	356,460	345,953
Total liabilities and stockholders' equity	$ 785,228	$ 766,622