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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
Revenue Recognition (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Sep. 30, 2024
Revenue Recognition and Deferred Revenue [Abstract]
Unbilled Receivables, Current	$ 14,467
Costs and estimated earnings in excess of billings	59,630		$ 60,139
Billings in excess of costs and estimated earnings	(170,393)		$ (158,972)
Contract with Customer, Liability, Revenue Recognized	116,848	$ 77,964
Performance Obligation Next 12 Months	994,694
Revenue, Remaining Performance Obligation, Amount	1,214,828
Disaggregation of Revenue [Line Items]
Revenues	749,547	634,444
Contract with Customer, Liability, Revenue Recognized	116,848	77,964
Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	88,491	84,952
Communications [Member]
Disaggregation of Revenue [Line Items]
Revenues	232,960	170,748
Infrastructure Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues	108,125	62,888
Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	319,971	315,856
Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	662,694	575,869
Fixed-price Contract [Member] \| Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	76,190	73,910
Fixed-price Contract [Member] \| Communications [Member]
Disaggregation of Revenue [Line Items]
Revenues	166,333	125,223
Fixed-price Contract [Member] \| Infrastructure Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues	100,200	60,880
Fixed-price Contract [Member] \| Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	319,971	315,856
Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	86,853	58,575
Time-and-materials Contract [Member] \| Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	12,301	11,042
Time-and-materials Contract [Member] \| Communications [Member]
Disaggregation of Revenue [Line Items]
Revenues	66,627	45,525
Time-and-materials Contract [Member] \| Infrastructure Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues	7,925	2,008
Time-and-materials Contract [Member] \| Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0
industrial Services [Member] \| Infrastructure Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues	18,668	11,098
Custom Power Solutions [Member] \| Infrastructure Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues	89,457	51,790
Single Family Contracts [Member] \| Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	169,217	173,984
Multi Family and Other [Member] \| Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	76,571	69,289
Single Family Contracts Plumbing HVAC \| Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 74,183	$ 72,583