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Amount, before allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

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- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

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- Definition

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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Amount received for services rendered and products shipped, but not yet billed, for non-contractual agreements due within one year or the normal operating cycle, if longer.

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Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Revenue Recognition (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Revenue Recognition and Deferred Revenue [Abstract]
Unbilled Receivables, Current	$ 11,608		$ 11,608
Costs and estimated earnings in excess of billings	47,956		47,956		$ 52,076
Billings in excess of costs and estimated earnings	(94,829)		(94,829)		$ (84,936)
Contract with Customer, Liability, Revenue Recognized			52,350	$ 45,115
Performance Obligation Next 12 Months	833,212		833,212
Revenue, Remaining Performance Obligation, Amount	1,012,111		1,012,111
Disaggregation of Revenue [Line Items]
Revenues	568,881	$ 501,593	1,143,755	982,102
Contract with Customer, Liability, Revenue Recognized			52,350	45,115
Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	69,033	68,815	129,300	138,063
Communications [Member]
Disaggregation of Revenue [Line Items]
Revenues	141,120	130,639	288,365	258,028
Infrastructure Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues	52,616	41,733	101,900	83,829
Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	306,112	260,406	624,190	502,182
Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	512,409	450,398	1,019,904	885,909
Fixed-price Contract [Member] \| Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	62,954	64,346	117,551	129,206
Fixed-price Contract [Member] \| Communications [Member]
Disaggregation of Revenue [Line Items]
Revenues	92,392	85,722	179,666	174,144
Fixed-price Contract [Member] \| Infrastructure Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues	50,951	39,924	98,497	80,377
Fixed-price Contract [Member] \| Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	306,112	260,406	624,190	502,182
Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	56,472	51,195	123,851	96,193
Time-and-materials Contract [Member] \| Commercial and Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	6,079	4,469	11,749	8,857
Time-and-materials Contract [Member] \| Communications [Member]
Disaggregation of Revenue [Line Items]
Revenues	48,728	44,917	108,699	83,884
Time-and-materials Contract [Member] \| Infrastructure Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,665	1,809	3,403	3,452
Time-and-materials Contract [Member] \| Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
industrial Services [Member] \| Infrastructure Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues	11,562	15,837	22,516	30,653
Custom Power Solutions [Member] \| Infrastructure Solutions [Member]
Disaggregation of Revenue [Line Items]
Revenues	41,054	25,896	79,384	53,176
Single Family Contracts [Member] \| Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	211,426	192,368	438,254	365,896
Multi Family and Other [Member] \| Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 94,686	$ 68,038	$ 185,936	$ 136,286