Revenue Recognition (Tables)

6 Months Ended

Mar. 31, 2020

Revenue Recognition and Deferred Revenue [Abstract]

Disaggregation of Revenue [Table Text Block]

	Three Months Ended March 31,				Six Months Ended March 31,
	2020		2019		2020		2019
Commercial & Industrial	$	65,960	$	79,975	$	133,703	$	152,558
Communications	95,990		70,437		180,279		139,762
Infrastructure Solutions
Industrial Services	10,724		12,145		21,835		24,368
Custom Power Solutions	18,576		22,305		38,748		39,561
Total Infrastructure Solutions	29,300		34,450		60,583		63,929
Residential
Single-family	58,958		51,492		113,832		101,968
Multi-family and Other	41,069		20,560		78,923		42,539
Total Residential	100,027		72,052		192,755		144,507
Total Revenue	$	291,277	$	256,914	$	567,320	$	500,756

	Three Months Ended March 31, 2020
		Commercial & Industrial		Communications		Infrastructure Solutions		Residential		Total
Fixed-price		$	62,779	$	71,377	$	27,484	$	100,027	$	261,667
Time-and-material			3,181		24,613		1,816		—		29,610
Total revenue		$	65,960	$	95,990	$	29,300	$	100,027	$	291,277
	Three Months Ended March 31, 2019
		Commercial & Industrial		Communications		Infrastructure Solutions		Residential		Total
Fixed-price		$	76,467	$	48,602	$	32,097	$	72,052	$	229,218
Time-and-material			3,508		21,835		2,353		—		27,696
Total revenue		$	79,975	$	70,437	$	34,450	$	72,052	$	256,914
	Six Months Ended March 31, 2020
		Commercial & Industrial		Communications		Infrastructure Solutions		Residential		Total
Fixed-price		$	126,614	$	133,404	$	56,975	$	192,755	$	509,748
Time-and-material			7,089		46,875		3,608		—		57,572
Total revenue		$	133,703	$	180,279	$	60,583	$	192,755	$	567,320
	Six Months Ended March 31, 2019
		Commercial & Industrial		Communications		Infrastructure Solutions		Residential		Total
Fixed-price		$	142,297	$	97,431	$	59,609	$	144,507	$	443,844
Time-and-material			10,261		42,331		4,320		—		56,912
Total revenue		$	152,558	$	139,762	$	63,929	$	144,507	$	500,756

Contract with Customer, Asset and Liability [Table Text Block]

The net asset (liability) position for contracts in process consisted of the following:

	March 31,		September 30,
	2020		2019
Costs and estimated earnings on uncompleted contracts	$	837,980	$	761,401
Less: Billings to date and unbilled accounts receivable		(856,388)		(772,104)
	$	(18,408)	$	(10,703)

The net asset (liability) position for contracts in process included in the accompanying consolidated balance sheets was as follows:

	March 31,		September 30,
	2020		2019
Costs and estimated earnings in excess of billings	$	27,478	$	29,860
Billings in excess of costs and estimated earnings		(45,886)		(40,563)
	$	(18,408)	$	(10,703)