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v3.21.2

Business segment data (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 | Jun. 30, 2021 | Mar. 31, 2021 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | $ 1,586,013 |  |  | $ 1,587,289 |  |  | $ 4,237,608 | $ 4,147,591
Operating income | 189,169 |  |  | 203,711 |  |  | 412,023 | 399,036
Income from continuing operations | 138,962 |  |  | 153,015 |  |  | 291,249 | 278,395
Income (loss) from discontinued operations, net of tax | 314 |  |  | 63 |  |  | 348 | (484)
Net income | 139,276 | $ 100,190 | $ 52,131 | 153,078 | $ 99,703 | $ 25,130 | 291,597 | 277,911
Electric |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 98,930 |  |  | 87,447 |  |  | 267,254 | 249,793
Operating income | 27,310 |  |  | 21,159 |  |  | 53,982 | 48,827
Natural gas distribution |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 110,378 |  |  | 94,703 |  |  | 614,373 | 562,641
Operating income | (14,249) |  |  | (18,393) |  |  | 42,925 | 32,285
Pipeline |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 30,968 |  |  | 32,068 |  |  | 68,653 | 70,381
Operating income | 12,284 |  |  | 11,762 |  |  | 35,896 | 35,406
Construction materials and contracting |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 831,189 |  |  | 822,439 |  |  | 1,730,521 | 1,705,629
Operating income | 133,712 |  |  | 148,522 |  |  | 171,274 | 179,994
Construction services |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 514,523 |  |  | 550,608 |  |  | 1,556,737 | 1,559,217
Operating income | 30,120 |  |  | 40,507 |  |  | 108,172 | 102,185
Other |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 25 |  |  | 24 |  |  | 70 | (70)
Operating income | (8) |  |  | 154 |  |  | (226) | 339
Intersegment eliminations |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | (7,983) |  |  | (7,543) |  |  | (51,356) | (50,849)
Intersegment eliminations | Electric |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | (136) |  |  | (195) |  |  | (407) | (586)
Intersegment eliminations | Natural gas distribution |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | (142) |  |  | (185) |  |  | (425) | (555)
Intersegment eliminations | Pipeline |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | (3,908) |  |  | (3,622) |  |  | (38,000) | (36,820)
Intersegment eliminations | Construction materials and contracting |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | (110) |  |  | (110) |  |  | (314) | (262)
Intersegment eliminations | Construction services |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | (289) |  |  | (425) |  |  | (2,128) | (3,674)
Intersegment eliminations | Other |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | (3,398) |  |  | (3,006) |  |  | (10,082) | (8,952)
Total intersegment operating revenues |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 0 |  |  | 0 |  |  | 0 | 0
Regulated operation |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 237,065 |  |  | 210,115 |  |  | 940,017 | 870,151
Income from continuing operations | 15,399 |  |  | 6,985 |  |  | 89,207 | 77,991
Regulated operation | Electric |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 98,930 |  |  | 87,447 |  |  | 267,254 | 249,793
Income from continuing operations | 20,564 |  |  | 16,787 |  |  | 41,618 | 40,314
Regulated operation | Natural gas distribution |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 110,378 |  |  | 94,703 |  |  | 614,373 | 562,641
Income from continuing operations | (15,390) |  |  | (17,614) |  |  | 20,081 | 13,795
Regulated operation | Pipeline |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 27,757 |  |  | 27,965 |  |  | 58,390 | 57,717
Income from continuing operations | 10,225 |  |  | 7,812 |  |  | 27,508 | 23,882
Regulated operation | Intersegment eliminations |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 4,123 |  |  | 3,923 |  |  | 38,362 | 37,724
Regulated operation | Intersegment eliminations | Electric |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 136 |  |  | 195 |  |  | 407 | 586
Regulated operation | Intersegment eliminations | Natural gas distribution |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 142 |  |  | 185 |  |  | 425 | 555
Regulated operation | Intersegment eliminations | Pipeline |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 3,845 |  |  | 3,543 |  |  | 37,530 | 36,583
Nonregulated operation |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 1,348,948 |  |  | 1,377,174 |  |  | 3,297,591 | 3,277,440
Income from continuing operations | 123,563 |  |  | 146,030 |  |  | 202,042 | 200,404
Nonregulated operation | Pipeline |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 3,211 |  |  | 4,103 |  |  | 10,263 | 12,664
Income from continuing operations | 356 |  |  | 189 |  |  | 1,166 | 444
Nonregulated operation | Construction materials and contracting |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 831,189 |  |  | 822,439 |  |  | 1,730,521 | 1,705,629
Income from continuing operations | 96,282 |  |  | 107,307 |  |  | 116,865 | 122,113
Nonregulated operation | Construction services |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 514,523 |  |  | 550,608 |  |  | 1,556,737 | 1,559,217
Income from continuing operations | 23,130 |  |  | 29,789 |  |  | 81,839 | 74,544
Nonregulated operation | Other |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 25 |  |  | 24 |  |  | 70 | (70)
Income from continuing operations | 3,795 |  |  | 8,745 |  |  | 2,172 | 3,303
Nonregulated operation | Intersegment eliminations |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 3,860 |  |  | 3,620 |  |  | 12,994 | 13,125
Nonregulated operation | Intersegment eliminations | Pipeline |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 63 |  |  | 79 |  |  | 470 | 237
Nonregulated operation | Intersegment eliminations | Construction materials and contracting |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 110 |  |  | 110 |  |  | 314 | 262
Nonregulated operation | Intersegment eliminations | Construction services |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | 289 |  |  | 425 |  |  | 2,128 | 3,674
Nonregulated operation | Intersegment eliminations | Other |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Revenues | $ 3,398 |  |  | $ 3,006 |  |  | $ 10,082 | $ 8,952

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