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Segmented information - Results of Operations and Assets for Segments (Detail) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017
Revenue |  |
Revenue | $ 1,647,387 | $ 1,521,938
Fuel, power and water purchased | 484,138 | 393,225
Net revenue | 1,163,249 | 1,128,713
Operating expenses | 472,466 | 450,231
Administrative expenses | 52,710 | 49,640
Depreciation and amortization | 260,772 | 251,314
Gain on foreign exchange | (58) | 323
Operating income | 377,359 | 377,205
Interest expense | 152,118 | 155,822
Interest, dividend, equity and other income | (53,139) | (9,238)
Change in value of investment carried at fair value | 137,957 | 0
Other expenses | 7,962 | 55,489
Earnings (loss) before income taxes | 132,461 | 175,132
Property, plant and equipment | 6,393,558 | 6,304,897
Investment carried at fair value | 814,530 | 0
Equity-method investees | 30,492 | 32,267
Total assets | 9,388,968 | 8,395,567
Capital expenditures | 466,369 | 565,103
Revenue related to net hedging gains, not recognized as revenue from contract with customers | 14,953 |
Liberty Utilities Group |  |
Revenue |  |
Revenue | 1,400,164 | 1,290,786
Fuel, power and water purchased | 456,974 | 373,635
Net revenue | 943,190 | 917,151
Operating expenses | 401,486 | 383,380
Administrative expenses | 33,234 | 33,037
Depreciation and amortization | 177,719 | 171,111
Gain on foreign exchange | 0 | 0
Operating income | 330,751 | 329,623
Interest expense | 99,063 | 97,698
Interest, dividend, equity and other income | (5,558) | (4,208)
Change in value of investment carried at fair value | 0 |
Other expenses | 5,699 | 6,087
Earnings (loss) before income taxes | 231,547 | 230,046
Property, plant and equipment | 4,210,115 | 4,023,479
Investment carried at fair value | 0 |
Equity-method investees | 959 | 2,220
Total assets | 6,012,641 | 5,817,599
Capital expenditures | 370,221 | 407,408
Revenue related to alternative revenue programs, not recognized as revenue from contract with customers | 7,425 |
Liberty Power Group |  |
Revenue |  |
Revenue | 247,223 | 231,152
Fuel, power and water purchased | 27,164 | 19,590
Net revenue | 220,059 | 211,562
Operating expenses | 70,980 | 66,851
Administrative expenses | 18,539 | 15,992
Depreciation and amortization | 82,044 | 79,183
Gain on foreign exchange | 0 | 0
Operating income | 48,496 | 49,536
Interest expense | 50,920 | 36,646
Interest, dividend, equity and other income | (45,741) | (2,871)
Change in value of investment carried at fair value | 0 |
Other expenses | 1,576 | 1,713
Earnings (loss) before income taxes | 41,741 | 14,048
Property, plant and equipment | 2,152,420 | 2,246,869
Investment carried at fair value | 814,530 |
Equity-method investees | 29,273 | 29,710
Total assets | 3,269,786 | 2,474,293
Capital expenditures | 96,148 | 157,695
Corporate |  |
Revenue |  |
Revenue | 0 | 0
Fuel, power and water purchased | 0 | 0
Net revenue | 0 | 0
Operating expenses | 0 | 0
Administrative expenses | 937 | 611
Depreciation and amortization | 1,009 | 1,020
Gain on foreign exchange | (58) | 323
Operating income | (1,888) | (1,954)
Interest expense | 2,135 | 21,478
Interest, dividend, equity and other income | (1,840) | (2,159)
Change in value of investment carried at fair value | 137,957 |
Other expenses | 687 | 47,689
Earnings (loss) before income taxes | (140,827) | (68,962)
Property, plant and equipment | 31,023 | 34,549
Investment carried at fair value | 0 |
Equity-method investees | 260 | 337
Total assets | 106,541 | 103,675
Capital expenditures | $ 0 | $ 0

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