Business Segment Data - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Business segment data [Line Items]
Revenues	$ 4,657,340	$ 4,441,784	$ 3,454,436
Depreciation and amortization	213,598	210,028	198,240
Total operating income	425,978	369,999	331,051
Interest expense	114,308	80,698	70,709
Income taxes	59,473	49,761	43,544
Income from continuing operations	480,425	250,768	242,522
Discontinued operations, net of tax	(65,718)	116,721	135,609
Net income	414,707	367,489	378,131
Total capital expenditures	532,815	474,642	518,282
Total assets	7,833,159	9,660,781	8,910,435
Property, plant and equipment	7,341,116	6,874,629
Less accumulated depreciation and amortization	2,220,206	2,098,298	2,119,074
Net property, plant and equipment	5,120,910	4,776,331	4,506,079
Additional information [Abstract]
Net noncash acquisitions, capital expenditure-related accounts payable and AFUDC	13,100	(3,800)	30,600
Operating Segments
Business segment data [Line Items]
Revenues	4,720,713	4,505,706	3,515,695
Total assets	7,685,794	7,205,711	6,535,988
Operating Segments | Electric
Business segment data [Line Items]
Revenues	400,901	376,936	349,412
Depreciation and amortization	64,253	67,802	66,750
Total operating income	92,789	79,655	66,335
Interest expense	28,064	28,526	26,712
Income taxes	(1,019)	(5,420)	(7,626)
Total capital expenditures	109,805	133,970	82,427
Total assets	1,955,644	1,856,258	1,810,695
Property, plant and equipment	2,369,039	2,276,613	2,295,646
Operating Segments | Natural gas distribution
Business segment data [Line Items]
Revenues	1,287,121	1,273,530	971,640
Depreciation and amortization	95,300	89,466	86,065
Total operating income	92,181	91,889	89,173
Interest expense	57,601	42,126	37,265
Income taxes	6,927	7,805	8,366
Total capital expenditures	274,836	240,064	170,411
Total assets	3,532,142	3,214,452	2,929,519
Property, plant and equipment	3,462,187	3,208,059	3,015,164
Operating Segments | Pipeline
Business segment data [Line Items]
Revenues	115,072	96,695	83,066
Depreciation and amortization	26,811	26,857	20,569
Total operating income	69,162	55,466	48,078
Interest expense	13,270	10,102	6,705
Income taxes	12,409	10,522	9,672
Total capital expenditures	115,903	61,923	234,803
Total assets	1,045,704	961,893	913,945
Property, plant and equipment	1,218,387	1,108,141	1,051,868
Operating Segments | Construction services
Business segment data [Line Items]
Revenues	2,854,246	2,694,623	2,050,234
Depreciation and amortization	23,148	21,468	20,270
Total operating income	190,541	164,644	145,754
Interest expense	10,057	165	(130)
Income taxes	46,968	42,298	36,322
Total capital expenditures	35,096	36,413	29,140
Total assets	1,106,570	1,126,323	845,262
Property, plant and equipment	259,849	245,111	225,758
Operating Segments | Other
Business segment data [Line Items]
Revenues	0	0	84
Depreciation and amortization	4,086	4,435	4,586
Total operating income	(18,695)	(21,655)	(18,289)
Interest expense	18,964	415	260
Income taxes	(5,812)	(5,444)	(3,190)
Total capital expenditures	(2,825)	2,272	1,501
Total assets	193,099	2,501,855	2,411,014
Property, plant and equipment	31,654	36,705	36,717
Intersegment eliminations
Business segment data [Line Items]
Revenues	(71,314)	(69,762)	(65,865)
Interest expense	(13,648)	(636)	(103)
Total assets	(579,235)	(1,184,512)	(992,084)
Regulated Operation
Business segment data [Line Items]
Revenues	1,789,637	1,736,397	1,390,992
Income from continuing operations	166,312	138,501	143,298
Regulated Operation | Operating Segments
Business segment data [Line Items]
Revenues	1,789,637	1,736,397	1,390,992
Regulated Operation | Operating Segments | Electric
Business segment data [Line Items]
Revenues	400,901	376,936	349,412
Income from continuing operations	71,559	57,077	51,906
Regulated Operation | Operating Segments | Natural gas distribution
Business segment data [Line Items]
Revenues	1,287,121	1,273,530	971,640
Income from continuing operations	48,520	45,171	51,596
Regulated Operation | Operating Segments | Pipeline
Business segment data [Line Items]
Revenues	101,615	85,931	69,940
Income from continuing operations	46,233	36,253	39,796
Regulated Operation | Intersegment eliminations
Business segment data [Line Items]
Revenues	(62,901)	(58,780)	(59,459)
Regulated Operation | Intersegment eliminations | Electric
Business segment data [Line Items]
Revenues	(274)	(137)	(170)
Regulated Operation | Intersegment eliminations | Natural gas distribution
Business segment data [Line Items]
Revenues	(416)	(274)	(300)
Regulated Operation | Intersegment eliminations | Pipeline
Business segment data [Line Items]
Revenues	(62,211)	(58,369)	(58,989)
Nonregulated Operation
Business segment data [Line Items]
Revenues	2,867,703	2,705,387	2,063,444
Income from continuing operations	314,113	112,267	99,224
Nonregulated Operation | Operating Segments
Business segment data [Line Items]
Revenues	2,867,703	2,705,387	2,063,444
Nonregulated Operation | Operating Segments | Pipeline
Business segment data [Line Items]
Revenues	13,457	10,764	13,126
Income from continuing operations	1,142	(59)	1,327
Nonregulated Operation | Operating Segments | Construction services
Business segment data [Line Items]
Revenues	2,854,246	2,694,623	2,050,234
Income from continuing operations	142,444	129,460	112,176
Nonregulated Operation | Operating Segments | Other
Business segment data [Line Items]
Revenues	0	0	84
Income from continuing operations	170,527	(17,134)	(14,279)
Nonregulated Operation | Intersegment eliminations
Business segment data [Line Items]
Revenues	(8,413)	(10,982)	(6,406)
Nonregulated Operation | Intersegment eliminations | Pipeline
Business segment data [Line Items]
Revenues	(329)	(515)	(481)
Nonregulated Operation | Intersegment eliminations | Construction services
Business segment data [Line Items]
Revenues	(143)	(4,627)	(1,403)
Nonregulated Operation | Intersegment eliminations | Other
Business segment data [Line Items]
Revenues	$ (7,941)	$ (5,840)	$ (4,522)