Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2023
Segment Reporting Information [Line Items]
Cost of services	$ 490,640	$ 479,436
Gross profit	143,804	95,438
Selling, general and administrative expenses	85,850	67,768
Contingent consideration	35	69
Loss (gain) on sale of assets	(71)	(13,060)
Operating income (loss)	57,990	40,661
Depreciation and amortization expense	7,617	6,388
Capital expenditures	6,515	2,712
Total assets	1,042,019	896,816	$ 981,600
Revenues	634,444	574,874
Noncontrolling Interest, Change in Redemption Value	2,782	3,055
Commercial and Industrial [Member]
Segment Reporting Information [Line Items]
Cost of services	71,045	56,653
Gross profit	13,907	3,614
Selling, general and administrative expenses	6,847	5,689
Loss (gain) on sale of assets	15	(13,035)
Operating income (loss)	7,045	10,960
Depreciation and amortization expense	475	392
Capital expenditures	821	723
Total assets	101,621	79,548
Revenues	84,952	60,267
Communications [Member]
Segment Reporting Information [Line Items]
Cost of services	134,473	125,507
Gross profit	36,275	21,738
Selling, general and administrative expenses	14,901	12,297
Loss (gain) on sale of assets	(4)	0
Operating income (loss)	21,378	9,441
Depreciation and amortization expense	723	430
Capital expenditures	1,000	642
Total assets	215,475	203,500
Revenues	170,748	147,245
Infrastructure Solutions [Member]
Segment Reporting Information [Line Items]
Cost of services	44,697	38,817
Gross profit	18,191	10,467
Selling, general and administrative expenses	7,285	5,761
Contingent consideration		0
Loss (gain) on sale of assets	0	(19)
Operating income (loss)	10,906	4,725
Depreciation and amortization expense	1,227	1,354
Capital expenditures	1,151	639
Total assets	185,875	163,201
Revenues	62,888	49,284
Residential [Member]
Segment Reporting Information [Line Items]
Cost of services	240,425	258,459
Gross profit	75,431	59,619
Selling, general and administrative expenses	51,378	39,051
Contingent consideration	35	69
Loss (gain) on sale of assets	(82)	(6)
Operating income (loss)	24,100	20,505
Depreciation and amortization expense	4,962	4,144
Capital expenditures	3,364	708
Total assets	388,808	395,243
Revenues	315,856	318,078
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Cost of services	0	0
Gross profit	0	0
Selling, general and administrative expenses	5,439	4,970
Contingent consideration		0
Loss (gain) on sale of assets	0	0
Operating income (loss)	(5,439)	(4,970)
Depreciation and amortization expense	230	68
Capital expenditures	179	0
Total assets	150,240	55,324
Revenues	$ 0	$ 0