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Revenue: Disaggregation of Revenue (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Revenue from contracts with customers | $ 1,930,834 | $ 1,680,804 | $ 1,726,392
Revenue | 1,949,102 | 1,696,941 | 1,734,900
Services transferred at a point in time |  |  |
Revenue from contracts with customers | 27,141 | 27,089 | 27,180
Services transferred over time |  |  |
Revenue from contracts with customers | 1,903,693 | 1,653,715 | 1,699,212
Other revenues |  |  |
Revenue | 18,268 | 16,137 | 8,508
Intercompany Eliminations |  |  |
Revenue from contracts with customers | (17,628) | (16,298) | (14,485)
Revenue | (18,021) | (16,586) | (14,485)
Intercompany Eliminations | Services transferred at a point in time |  |  |
Revenue from contracts with customers | 0 | 0 | 0
Intercompany Eliminations | Services transferred over time |  |  |
Revenue from contracts with customers | (17,628) | (16,298) | (14,485)
Intercompany Eliminations | Other revenues |  |  |
Revenue | (393) | (288) | 0
Electric Utilities |  |  |
Revenue from contracts with customers | 836,923 | 732,681 | 731,231
Revenue | 842,258 | 738,857 | 739,355
Electric Utilities | Services transferred at a point in time |  |  |
Revenue from contracts with customers | 27,141 | 27,089 | 27,180
Electric Utilities | Services transferred over time |  |  |
Revenue from contracts with customers | 809,782 | 705,592 | 704,051
Electric Utilities | Other revenues |  |  |
Revenue | 5,335 | 6,176 | 8,124
Gas Utilities |  |  |
Revenue from contracts with customers | 1,111,539 | 964,421 | 1,009,646
Revenue | 1,124,865 | 974,670 | 1,010,030
Gas Utilities | Services transferred at a point in time |  |  |
Revenue from contracts with customers | 0 | 0 | 0
Gas Utilities | Services transferred over time |  |  |
Revenue from contracts with customers | 1,111,539 | 964,421 | 1,009,646
Gas Utilities | Other revenues |  |  |
Revenue | 13,326 | 10,249 | 384
Retail |  |  |
Revenue from contracts with customers | 1,625,173 | 1,402,824 | 1,450,776
Retail | Intercompany Eliminations |  |  |
Revenue from contracts with customers | 0 | 0 | 0
Retail | Electric Utilities |  |  |
Revenue from contracts with customers | 711,448 | 636,902 | 632,936
Retail | Gas Utilities |  |  |
Revenue from contracts with customers | 913,725 | 765,922 | 817,840
Transportation |  |  |
Revenue from contracts with customers | 157,625 | 154,055 | 142,348
Transportation | Intercompany Eliminations |  |  |
Revenue from contracts with customers | (428) | (526) | (1,042)
Transportation | Electric Utilities |  |  |
Revenue from contracts with customers | 0 | 0 | 0
Transportation | Gas Utilities |  |  |
Revenue from contracts with customers | 158,053 | 154,581 | 143,390
Wholesale |  |  |
Revenue from contracts with customers | 30,848 | 24,845 | 28,464
Wholesale | Intercompany Eliminations |  |  |
Revenue from contracts with customers | 0 | 0 | 0
Wholesale | Electric Utilities |  |  |
Revenue from contracts with customers | 30,848 | 24,845 | 28,464
Wholesale | Gas Utilities |  |  |
Revenue from contracts with customers | 0 | 0 | 0
Market - off-system sales |  |  |
Revenue from contracts with customers | 42,078 | 15,772 | 16,772
Market - off-system sales | Intercompany Eliminations |  |  |
Revenue from contracts with customers | 0 | 0 | 0
Market - off-system sales | Electric Utilities |  |  |
Revenue from contracts with customers | 41,682 | 15,512 | 16,081
Market - off-system sales | Gas Utilities |  |  |
Revenue from contracts with customers | 396 | 260 | 691
Transmission/Other |  |  |
Revenue from contracts with customers | 75,110 | 83,308 | 88,032
Transmission/Other | Intercompany Eliminations |  |  |
Revenue from contracts with customers | (17,200) | (15,772) | (13,443)
Transmission/Other | Electric Utilities |  |  |
Revenue from contracts with customers | 52,945 | 55,422 | 53,750
Transmission/Other | Gas Utilities |  |  |
Revenue from contracts with customers | $ 39,365 | $ 43,658 | $ 47,725

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