| Mar'20 | Dec'19 | Sep'19 | Jun'19 | Mar'19 | Dec'18 | Sep'18 | Jun'18 | Mar'18 |
|---|---|---|---|---|---|---|---|---|
Operating revenues [Abstract] | ||||||||
Operating revenues | ||||||||
746,175 | 746,372 | 725,810 | 726,732 | 727,856 | 706,143 | 0 | 0 | 0 |
Operating expenses: | ||||||||
Cost of gas | ||||||||
257,992 | 254,911 | 242,989 | 245,924 | 252,870 | 255,519 | 0 | 0 | 0 |
Operations and maintenance | ||||||||
175,630 | 178,191 | 173,432 | 170,115 | 168,657 | 156,698 | 0 | 0 | 0 |
Environmental Remediation Expense | ||||||||
7,395 | 12,337 | 10,857 | 10,912 | 15,450 | 11,127 | 0 | 0 | 0 |
General taxes | ||||||||
33,256 | 32,388 | 32,279 | 31,875 | 31,725 | 32,172 | 0 | 0 | 0 |
Excise Taxes | ||||||||
0 | - | - | - | 0 | - | - | - | - |
Revenue taxes | ||||||||
- | - | 29,307 | 29,295 | - | 30,082 | 0 | 0 | 0 |
Depreciation and amortization | ||||||||
94,599 | 91,496 | 88,983 | 87,093 | 85,853 | 85,156 | 0 | 0 | 0 |
Other operating expenses | ||||||||
3,286 | 3,250 | 3,201 | 3,233 | 3,266 | 3,227 | 0 | 0 | 0 |
Total operating expenses | ||||||||
602,300 | 602,898 | 581,048 | 578,447 | 587,400 | 573,981 | 0 | 0 | 0 |
Income from operations | ||||||||
143,875 | 143,474 | 144,762 | 148,285 | 140,456 | 132,162 | 0 | 0 | 0 |
Other income (expense), net | ||||||||
-12,664 | -22,836 | -21,244 | -19,289 | -16,514 | -3,601 | 0 | 0 | 0 |
Interest expense, net | ||||||||
-42,948 | -42,685 | -41,815 | -39,873 | -37,990 | -37,059 | 0 | 0 | 0 |
Income before income taxes | ||||||||
88,263 | 77,953 | 81,703 | 89,123 | 85,952 | 91,502 | 0 | 0 | 0 |
Income tax expense | ||||||||
18,094 | 12,642 | 17,957 | 18,015 | 17,234 | 24,191 | 0 | 0 | 0 |
Net income from continuing operations | ||||||||
70,169 | 65,311 | 63,746 | 71,108 | 68,718 | 67,311 | 0 | 0 | 0 |
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent | ||||||||
-4,137 | -3,576 | -2,927 | -2,782 | -2,485 | -2,742 | 0 | 0 | 0 |
Net Income (Loss) Attributable to Parent | ||||||||
66,032 | 61,735 | 60,819 | 68,326 | 66,233 | 64,569 | 0 | 0 | 0 |
Other comprehensive income: | ||||||||
Amortization of non-qualified employee benefit plan liability, net of taxes | ||||||||
521 | 476 | 657 | 697 | 735 | 774 | 0 | 0 | 0 |
Comprehensive income | ||||||||
63,898 | 59,556 | 61,952 | 69,499 | 67,444 | 65,819 | 0 | 0 | 0 |
Average common shares outstanding: | ||||||||
Basic (in shares) | ||||||||
30,491 | 30,472 | 30,429 | 29,337 | 28,906 | 28,853 | 28,815 | 28,791 | 28,753 |
Diluted (in shares) | ||||||||
30,535 | 30,643 | 30,429 | 29,394 | 28,970 | 29,083 | 28,815 | 28,791 | 28,803 |
Earnings from continuing operations per share of common stock: | ||||||||
Basic (in dollars per share) | ||||||||
1.58 | 1.23 | -0.61 | 0.07 | 1.50 | 1.28 | -0.39 | -0.01 | 1.46 |
Diluted (in dollars per share) | ||||||||
1.58 | 1.23 | -0.61 | 0.07 | 1.50 | 1.27 | -0.39 | -0.01 | 1.46 |
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic and Diluted Share [Abstract] | ||||||||
Basic (in dollars per share) | ||||||||
-0.02 | - | -0.02 | - | -0.01 | - | -0.02 | - | - |
Diluted (in dollars per share) | ||||||||
-0.02 | - | -0.02 | - | -0.01 | - | -0.02 | - | - |
Earnings Per Share [Abstract] | ||||||||
Basic (in dollars per share) | ||||||||
1.56 | 1.17 | -0.63 | 0.04 | 1.49 | 1.24 | -0.41 | -0.03 | 1.44 |
Diluted (in dollars per share) | ||||||||
1.56 | 1.17 | -0.63 | 0.04 | 1.49 | 1.24 | -0.41 | -0.03 | 1.44 |
Northwest Natural Gas Company [Member] | ||||||||
Operating revenues | ||||||||
737,627 | 739,944 | 720,826 | 724,461 | 726,782 | 705,571 | 0 | 0 | 0 |
Cost of gas | ||||||||
258,217 | 255,135 | 243,214 | 246,148 | 253,092 | 255,743 | 0 | 0 | 0 |
Operations and maintenance | ||||||||
164,913 | 169,091 | 165,553 | 165,552 | 166,159 | 155,225 | 0 | 0 | 0 |
Environmental Remediation Expense | ||||||||
7,395 | 12,337 | 10,857 | 10,912 | 15,450 | 11,127 | 0 | 0 | 0 |
General taxes | ||||||||
32,886 | 32,075 | 32,017 | 31,720 | 31,615 | 32,086 | 0 | 0 | 0 |
Excise Taxes | ||||||||
0 | - | - | - | 0 | - | - | - | - |
Revenue taxes | ||||||||
- | - | 29,307 | 29,295 | - | 30,082 | 0 | 0 | 0 |
Depreciation and amortization | ||||||||
93,091 | 90,405 | 88,395 | 86,775 | 85,622 | 84,986 | 0 | 0 | 0 |
Other operating expenses | ||||||||
3,260 | 3,230 | 3,181 | 3,219 | 3,260 | 3,223 | 0 | 0 | 0 |
Total operating expenses | ||||||||
589,904 | 592,598 | 572,524 | 573,621 | 584,777 | 572,472 | 0 | 0 | 0 |
Income from operations | ||||||||
147,723 | 147,346 | 148,302 | 150,840 | 142,005 | 133,099 | 0 | 0 | 0 |
Other income (expense), net | ||||||||
-12,763 | -22,968 | -21,336 | -19,333 | -16,552 | -3,599 | 0 | 0 | 0 |
Interest expense, net | ||||||||
-41,067 | -41,339 | -40,919 | -39,467 | -37,851 | -36,992 | 0 | 0 | 0 |
Income before income taxes | ||||||||
93,893 | 83,039 | 86,047 | 92,040 | 87,602 | 92,508 | 0 | 0 | 0 |
Income tax expense | ||||||||
19,635 | 14,065 | 19,105 | 18,785 | 17,672 | 24,459 | 0 | 0 | 0 |
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent | ||||||||
- | - | 66,942 | 73,255 | - | 68,049 | 0 | 0 | 0 |
Loss from discontinued operations, net of tax | ||||||||
- | - | 0 | -519 | - | -1,723 | 0 | 0 | 0 |
Net Income (Loss) Attributable to Parent | ||||||||
74,258 | 68,974 | 66,942 | 72,736 | 68,684 | 66,326 | 0 | 0 | 0 |
Amortization of non-qualified employee benefit plan liability, net of taxes | ||||||||
521 | 476 | 657 | 697 | 735 | 774 | 0 | 0 | 0 |
Comprehensive income | ||||||||
72,124 | 66,795 | 68,075 | 73,909 | 69,895 | 67,576 | 0 | 0 | 0 |