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Revenue: Disaggregation of Revenue (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | $ 470,324 | $ 368,422 | $ 1,292,093 | $ 998,640
Total revenues | 474,195 | 372,572 | 1,297,765 | 1,006,004
Services transferred at a point in time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 6,671 | 6,714 | 13,784 | 13,690
Services transferred over time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 463,653 | 361,708 | 1,278,309 | 984,950
Other revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenues | 3,871 | 4,150 | 5,672 | 7,364
Retail - Electric , Natural Gas and Coal |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 398,106 | 307,816 | 1,131,925 | 853,701
Transportation |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 34,567 | 31,540 | 83,991 | 79,381
Wholesale |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 8,428 | 5,655 | 18,703 | 17,014
Market - off-system sales |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 8,844 | 7,353 | 16,236 | 12,198
Transmission/Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 20,379 | 16,058 | 41,238 | 36,346
Inter-company Revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | (4,248) | (4,400) | (8,496) | (8,799)
Total revenues | (4,353) | (4,494) | (8,713) | (8,985)
Inter-company Revenues | Services transferred at a point in time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Inter-company Revenues | Services transferred over time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | (4,248) | (4,400) | (8,496) | (8,799)
Inter-company Revenues | Other revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenues | (105) | (94) | (217) | (186)
Inter-company Revenues | Retail - Electric , Natural Gas and Coal |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Inter-company Revenues | Transportation |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | (100) | (109) | (199) | (219)
Inter-company Revenues | Wholesale |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Inter-company Revenues | Market - off-system sales |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Inter-company Revenues | Transmission/Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | (4,148) | (4,291) | (8,297) | (8,580)
Electric Utilities |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 201,309 | 188,116 | 406,977 | 422,714
Total revenues | 204,379 | 191,016 | 410,917 | 426,420
Electric Utilities | Services transferred at a point in time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 6,671 | 6,714 | 13,784 | 13,690
Electric Utilities | Services transferred over time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 194,638 | 181,402 | 393,193 | 409,024
Electric Utilities | Other revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenues | 3,070 | 2,900 | 3,940 | 3,706
Electric Utilities | Retail - Electric , Natural Gas and Coal |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 169,032 | 163,971 | 341,838 | 368,251
Electric Utilities | Transportation |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Electric Utilities | Wholesale |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 8,428 | 5,655 | 18,703 | 17,014
Electric Utilities | Market - off-system sales |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 8,666 | 7,266 | 15,820 | 12,038
Electric Utilities | Transmission/Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 15,183 | 11,224 | 30,616 | 25,411
Gas Utilities |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 273,263 | 184,706 | 893,612 | 584,725
Total revenues | 274,169 | 186,050 | 895,561 | 588,569
Gas Utilities | Services transferred at a point in time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Gas Utilities | Services transferred over time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 273,263 | 184,706 | 893,612 | 584,725
Gas Utilities | Other revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenues | 906 | 1,344 | 1,949 | 3,844
Gas Utilities | Retail - Electric , Natural Gas and Coal |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 229,074 | 143,845 | 790,087 | 485,450
Gas Utilities | Transportation |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 34,667 | 31,649 | 84,190 | 79,600
Gas Utilities | Wholesale |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 0 | 0 | 0 | 0
Gas Utilities | Market - off-system sales |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | 178 | 87 | 416 | 160
Gas Utilities | Transmission/Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Revenue from contracts with customers | $ 9,344 | $ 9,125 | $ 18,919 | $ 19,515

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