Operating Segments (Tables)

6 Months Ended

Mar. 31, 2021

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

		Three Months Ended March 31, 2021
		Communications		Residential		Infrastructure Solutions		Commercial & Industrial		Corporate		Total
Revenues		$	94,886	$	150,336	$	34,716	$	52,023	$	—	$	331,961
Cost of services		75,339		120,146		25,161		46,441		—		267,087
Gross profit		19,547		30,190		9,555		5,582		—		64,874
Selling, general and administrative		9,615		21,609		6,242		6,744		3,445		47,655
Contingent consideration		—		73		—		—		—		73
Loss (gain) on sale of assets		—		52		(26)		(8)		—		18
Operating income (loss)		$	9,932	$	8,456	$	3,339	$	(1,154)	$	(3,445)	$	17,128
Other data:
	Depreciation and amortization expense	$	347	$	3,205	$	1,554	$	683	$	39	$	5,828
	Capital expenditures	$	133	$	1,040	$	163	$	397	$	89	$	1,822
	Total assets	$	128,568	$	215,399	$	134,037	$	69,405	$	68,243	$	615,652

		Three Months Ended March 31, 2020
		Communications		Residential		Infrastructure Solutions		Commercial & Industrial		Corporate		Total
Revenues		$	95,990	$	100,027	$	29,300	$	65,960	$	—	$	291,277
Cost of services		79,352		77,114		22,055		61,492		—		240,013
Gross profit		16,638		22,913		7,245		4,468		—		51,264
Selling, general and administrative		9,419		15,754		4,918		8,586		3,359		42,036
Gain on sale of assets		—		—		—		(1)		—		(1)
Operating income (loss)		$	7,219	$	7,159	$	2,327	$	(4,117)	$	(3,359)	$	9,229
Other data:
	Depreciation and amortization expense	$	343	$	431	$	1,754	$	689	$	18	$	3,235
	Capital expenditures	$	186	$	657	$	153	$	212	$	299	$	1,507
	Total assets	$	126,871	$	101,246	$	127,426	$	75,075	$	95,726	$	526,344

		Six Months Ended March 31, 2021
		Communications		Residential		Infrastructure Solutions		Commercial & Industrial		Corporate		Total
Revenues		$	193,242	$	269,827	$	69,117	$	114,613	$	—	$	646,799
Cost of services		155,156		216,109		48,625		103,356		—		523,246
Gross profit		38,086		53,718		20,492		11,257		—		123,553
Selling, general and administrative		18,956		38,936		11,853		13,168		7,528		90,441
Contingent consideration		—		73		—		—		—		73
Loss (gain) on sale of assets		—		52		(27)		(17)		—		8
Operating income (loss)		$	19,130	$	14,657	$	8,666	$	(1,894)	$	(7,528)	$	33,031
Other data:
	Depreciation and amortization expense	$	694	$	4,709	$	2,995	$	1,377	$	73	$	9,848
	Capital expenditures	$	265	$	1,477	$	508	$	665	$	89	$	3,004
	Total assets	$	128,568	$	215,399	$	134,037	$	69,405	$	68,243	$	615,652

		Six Months Ended March 31, 2020
		Communications		Residential		Infrastructure Solutions		Commercial & Industrial		Corporate		Total
Revenues		$	180,279	$	192,755	$	60,583	$	133,703	$	—	$	567,320
Cost of services		148,074		149,699		45,568		122,500		—		465,841
Gross profit		32,205		43,056		15,015		11,203		—		101,479
Selling, general and administrative		17,988		29,474		9,411		15,874		7,161		79,908
Gain on sale of assets		(9)		—		—		(28)		—		(37)
Operating income (loss)		$	14,226	$	13,582	$	5,604	$	(4,643)	$	(7,161)	$	21,608
Other data:
	Depreciation and amortization expense	$	680	$	641	$	2,874	$	1,365	$	37	$	5,597
	Capital expenditures	$	468	$	869	$	590	$	672	$	299	$	2,898
	Total assets	$	126,871	$	101,246	$	127,426	$	75,075	$	95,726	$	526,344