Document and Entity Information
Document and Entity Information - USD ($) | 12 Months Ended | ||
Dec. 31, 2023 | Feb. 14, 2024 | Jun. 30, 2023 | |
Document Information [Line Items] | |||
Document Type | 10-K | ||
Document Period End Date | Dec. 31, 2023 | ||
Entity File Number | 1-38681 | ||
Document Annual Report | true | ||
Amendment Flag | false | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Central Index Key | 0001733998 | ||
Entity Current Reporting Status | Yes | ||
Entity Filer Category | Large Accelerated Filer | ||
Entity Registrant Name | NORTHWEST NATURAL HOLDING COMPANY | ||
Entity Voluntary Filers | No | ||
Entity Well-known Seasoned Issuer | Yes | ||
Entity Common Stock, Shares Outstanding | 37,676,740 | ||
Document Fiscal Year Focus | 2023 | ||
Document Fiscal Period Focus | FY | ||
Entity Public Float | $ 1,534,376,401 | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | true | ||
Document Financial Statement Error Correction [Flag] | false | ||
Document Transition Report | false | ||
Entity Incorporation, State or Country Code | OR | ||
Entity Tax Identification Number | 82-4710680 | ||
Entity Address, Address Line One | 250 S.W. Taylor Street | ||
Entity Address, City or Town | Portland | ||
Entity Address, State or Province | OR | ||
Entity Address, Postal Zip Code | 97204 | ||
City Area Code | (503) | ||
Local Phone Number | 226-4211 | ||
Title of 12(b) Security | Common Stock | ||
Trading Symbol | NWN | ||
Security Exchange Name | NYSE | ||
Entity Interactive Data Current | Yes | ||
Entity Shell Company | false | ||
Documents Incorporated by Reference [Text Block] | Portions of Northwest Natural Holding Company's Proxy Statement, to be filed in connection with the 2024 Annual Meeting of Shareholders, are incorporated by reference in Part III. | ||
Northwest Natural Gas Company [Member] | |||
Document Information [Line Items] | |||
Document Type | 10-K | ||
Document Period End Date | Dec. 31, 2023 | ||
Entity File Number | 1-15973 | ||
Amendment Flag | false | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Central Index Key | 0000073020 | ||
Entity Current Reporting Status | Yes | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Registrant Name | NORTHWEST NATURAL GAS COMPANY | ||
Entity Voluntary Filers | No | ||
Entity Well-known Seasoned Issuer | No | ||
Document Fiscal Year Focus | 2023 | ||
Document Fiscal Period Focus | FY | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | false | ||
Document Financial Statement Error Correction [Flag] | false | ||
Entity Incorporation, State or Country Code | OR | ||
Entity Tax Identification Number | 93-0256722 | ||
Entity Address, Address Line One | 250 S.W. Taylor Street | ||
Entity Address, City or Town | Portland | ||
Entity Address, State or Province | OR | ||
Entity Address, Postal Zip Code | 97204 | ||
City Area Code | (503) | ||
Local Phone Number | 226-4211 | ||
Entity Interactive Data Current | Yes | ||
Entity Shell Company | false |
Audit Information
Audit Information | 12 Months Ended |
Dec. 31, 2023 | |
Auditor [Line Items] | |
Auditor Firm ID | 238 |
Auditor Name | PricewaterhouseCoopers LLP |
Auditor Location | Portland, Oregon |
Northwest Natural Gas Company [Member] | |
Auditor [Line Items] | |
Auditor Firm ID | 238 |
Auditor Name | PricewaterhouseCoopers LLP |
Auditor Location | Portland, Oregon |
Consolidated Statements of Comp
Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Operating revenues [Abstract] | |||
Operating revenues | $ 1,197,475,000 | $ 1,037,353,000 | $ 860,400,000 |
Operating expenses: | |||
Cost of gas | 499,837,000 | 429,635,000 | 292,314,000 |
Operations and maintenance | 273,766,000 | 224,667,000 | 204,227,000 |
Environmental remediation | 12,899,000 | 12,389,000 | 9,938,000 |
General taxes | 46,248,000 | 41,031,000 | 38,633,000 |
Revenue taxes | 48,671,000 | 41,826,000 | 34,740,000 |
Depreciation | 125,581,000 | 116,707,000 | 113,534,000 |
Other operating expenses | 5,532,000 | 3,621,000 | 3,897,000 |
Total operating expenses | 1,012,534,000 | 869,876,000 | 697,283,000 |
Income from operations | 184,941,000 | 167,477,000 | 163,117,000 |
Other income (expense), net | 17,855,000 | 1,203,000 | (12,559,000) |
Interest expense, net | 76,566,000 | 53,247,000 | 44,486,000 |
Income before income taxes | 126,230,000 | 115,433,000 | 106,072,000 |
Income tax expense | 32,362,000 | 29,130,000 | 27,406,000 |
Net income | 93,868,000 | 86,303,000 | 78,666,000 |
Other comprehensive income (loss): | |||
Change in employee benefit plan liability, net of taxes | (1,233,000) | 4,195,000 | 593,000 |
Amortization of non-qualified employee benefit plan liability, net of taxes | 410,000 | 795,000 | 905,000 |
Unrealized gain on interest rate swaps, net of taxes | 59,000 | 129,000 | 0 |
Comprehensive income | 93,104,000 | 91,422,000 | 80,164,000 |
Supplemental Income Statement Elements [Abstract] | |||
Change in employee benefit plan liability, taxes | 443 | (1,511) | (219) |
Amortization of non-qualified employee benefit plan liability, taxes | (148) | (286) | $ (320) |
Unrealized Gain on Derivative, tax | $ (21) | $ (47) | |
Average common shares outstanding: | |||
Basic (in shares) | 36,213 | 33,934 | 30,702 |
Diluted (in shares) | 36,265 | 33,984 | 30,752 |
Earnings (loss) per share of common stock: | |||
Basic (in dollars per share) | $ 2.59 | $ 2.54 | $ 2.56 |
Diluted (in dollars per share) | $ 2.59 | $ 2.54 | $ 2.56 |
Northwest Natural Gas Company [Member] | |||
Operating revenues [Abstract] | |||
Operating revenues | $ 1,158,623,000 | $ 1,014,339,000 | $ 843,057,000 |
Operating expenses: | |||
Cost of gas | 500,061,000 | 429,861,000 | 292,538,000 |
Utility Operations and maintenance | 244,669,000 | 204,845,000 | 188,762,000 |
Environmental remediation | 12,899,000 | 12,389,000 | 9,938,000 |
General taxes | 44,980,000 | 40,151,000 | 38,150,000 |
Revenue taxes | 48,432,000 | 41,627,000 | 34,600,000 |
Depreciation | 119,514,000 | 112,957,000 | 110,504,000 |
Other operating expenses | 2,423,000 | 3,135,000 | 3,332,000 |
Total operating expenses | 972,978,000 | 844,965,000 | 677,824,000 |
Income from operations | 185,645,000 | 169,374,000 | 165,233,000 |
Other income (expense), net | 15,358,000 | (436,000) | (12,745,000) |
Interest expense, net | 60,594,000 | 46,338,000 | 42,983,000 |
Income before income taxes | 140,409,000 | 122,600,000 | 109,505,000 |
Income tax expense | 35,672,000 | 31,036,000 | 28,333,000 |
Net income | 104,737,000 | 91,564,000 | 81,172,000 |
Other comprehensive income (loss): | |||
Change in employee benefit plan liability, net of taxes | (1,233,000) | 4,195,000 | 593,000 |
Amortization of non-qualified employee benefit plan liability, net of taxes | 410,000 | 795,000 | 905,000 |
Comprehensive income | 103,914,000 | 96,554,000 | 82,670,000 |
Supplemental Income Statement Elements [Abstract] | |||
Change in employee benefit plan liability, taxes | 443 | (1,511) | (219) |
Amortization of non-qualified employee benefit plan liability, taxes | $ (148) | $ (286) | $ (320) |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Current assets: | ||
Cash and cash equivalents | $ 32,920 | $ 29,270 |
Accounts receivable | 121,341 | 168,906 |
Accrued unbilled revenue | $ 83,138 | 89,048 |
Receivables from affiliates - Affiliated Entity [Extensible Enumeration] | Affiliated Entity [Member] | |
Allowance for uncollectible accounts | $ (3,455) | (3,296) |
Regulatory assets | 178,270 | 117,491 |
Derivative instruments | 11,380 | 194,412 |
Inventories | 112,571 | 87,096 |
Other current assets | 65,275 | 61,286 |
Total current assets | 601,440 | 744,213 |
Non-current assets: | ||
Property, plant, and equipment | 4,556,609 | 4,261,566 |
Less: Accumulated depreciation | 1,198,555 | 1,147,166 |
Total property, plant, and equipment, net | 3,358,054 | 3,114,400 |
Regulatory Assets, Noncurrent | 333,443 | 340,432 |
Derivative instruments | 431 | 5,045 |
Other investments | 102,951 | 95,704 |
Operating lease right of use asset, net | 71,308 | 73,429 |
Assets under sales-type leases | 129,882 | 134,302 |
Goodwill | 163,344 | 149,283 |
Other non-current assets | 106,239 | 91,518 |
Total non-current assets | 4,265,652 | 4,004,113 |
Total assets | 4,867,092 | 4,748,326 |
Current liabilities: | ||
Short-term debt | 89,780 | 258,200 |
Current maturities of long-term debt | 150,865 | 90,697 |
Accounts payable | $ 145,361 | 180,667 |
Payables to affiliates - Affiliated Entity [Extensible Enumeration] | Affiliated Entity [Member] | |
Taxes accrued | $ 15,454 | 15,625 |
Interest accrued | 15,836 | 10,169 |
Regulatory liabilities | 84,962 | 248,582 |
Derivative instruments | 98,661 | 28,728 |
Operating lease liabilities | 2,333 | 1,514 |
Other current liabilities | 93,626 | 64,552 |
Total current liabilities | 696,878 | 898,734 |
Long-term debt | 1,425,435 | 1,246,167 |
Deferred credits and other non-current liabilities: | ||
Deferred Income Tax Liabilities, Net | 382,673 | 366,022 |
Regulatory liabilities | 695,896 | 689,578 |
Pension and other postretirement benefit liabilities | 158,116 | 149,143 |
Derivative instruments | 28,055 | 20,838 |
Operating lease liabilities | 77,167 | 78,965 |
Other non-current liabilities | 119,034 | 123,438 |
Total deferred credits and other non-current liabilities | 1,460,941 | 1,427,984 |
Commitments and contingencies (see Note 16 and Note 17) | ||
Equity: | ||
Common stock - no par value | 890,976 | 805,253 |
Retained earnings | 399,911 | 376,473 |
Accumulated other comprehensive loss | (7,049) | (6,285) |
Total equity | 1,283,838 | 1,175,441 |
Total liabilities and equity | $ 4,867,092 | $ 4,748,326 |
Par Value (in dollars per share) | $ 0 | $ 0 |
Shares Authorized (in shares) | 100,000,000 | 100,000,000 |
Shares issued (in shares) | 37,631,212 | 35,524,590 |
Shares outstanding (in shares) | 37,631,212 | 35,524,590 |
Northwest Natural Gas Company [Member] | ||
Current assets: | ||
Cash and cash equivalents | $ 19,841 | $ 12,977 |
Accounts receivable | 117,216 | 165,607 |
Accrued unbilled revenue | $ 81,524 | 87,482 |
Receivables from affiliates - Affiliated Entity [Extensible Enumeration] | Affiliated Entity [Member] | |
Receivables from affiliates | $ 824 | 634 |
Allowance for uncollectible accounts | (3,228) | (3,079) |
Regulatory assets | 178,270 | 117,491 |
Derivative instruments | 11,184 | 194,236 |
Inventories | 110,855 | 86,207 |
Other current assets | 60,138 | 57,269 |
Total current assets | 576,624 | 718,824 |
Non-current assets: | ||
Property, plant, and equipment | 4,393,759 | 4,148,547 |
Less: Accumulated depreciation | 1,181,962 | 1,137,231 |
Total property, plant, and equipment, net | 3,211,797 | 3,011,316 |
Regulatory Assets, Noncurrent | 333,418 | 340,407 |
Derivative instruments | 373 | 5,045 |
Other investments | 86,145 | 80,110 |
Operating lease right of use asset, net | 70,728 | 72,720 |
Assets under sales-type leases | 129,882 | 134,302 |
Other non-current assets | 102,410 | 89,994 |
Total non-current assets | 3,934,753 | 3,733,894 |
Total assets | 4,511,377 | 4,452,718 |
Current liabilities: | ||
Short-term debt | 16,780 | 170,200 |
Current maturities of long-term debt | 0 | 89,942 |
Accounts payable | 138,111 | 177,590 |
Payables to affiliates | $ 14,850 | 9,175 |
Payables to affiliates - Affiliated Entity [Extensible Enumeration] | Affiliated Entity [Member] | |
Taxes accrued | $ 15,293 | 15,426 |
Interest accrued | 15,111 | 8,900 |
Regulatory liabilities | 84,912 | 248,553 |
Derivative instruments | 98,661 | 28,728 |
Operating lease liabilities | 2,128 | 1,363 |
Other current liabilities | 89,371 | 62,019 |
Total current liabilities | 475,217 | 811,896 |
Long-term debt | 1,364,732 | 1,035,935 |
Deferred credits and other non-current liabilities: | ||
Deferred Income Tax Liabilities, Net | 371,867 | 362,353 |
Regulatory liabilities | 694,947 | 688,599 |
Pension and other postretirement benefit liabilities | 158,116 | 149,143 |
Derivative instruments | 28,055 | 20,838 |
Operating lease liabilities | 76,757 | 78,345 |
Other non-current liabilities | 109,066 | 114,527 |
Total deferred credits and other non-current liabilities | 1,438,808 | 1,413,805 |
Commitments and contingencies (see Note 16 and Note 17) | ||
Equity: | ||
Common stock - no par value | 644,903 | 614,903 |
Retained earnings | 594,954 | 582,593 |
Accumulated other comprehensive loss | (7,237) | (6,414) |
Total equity | 1,232,620 | 1,191,082 |
Total liabilities and equity | $ 4,511,377 | $ 4,452,718 |
Consolidated Statement of Share
Consolidated Statement of Shareholders' Equity - USD ($) $ in Thousands | Total | Common Stock Including APIC [Member] | Retained Earnings [Member] | Accumulated Other Comprehensive Income (Loss) [Member] | Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] Northwest Natural Gas Company Consolidated [Member] | Northwest Natural Gas Company [Member] Common Stock Including APIC [Member] | Northwest Natural Gas Company [Member] Retained Earnings [Member] | Northwest Natural Gas Company [Member] Accumulated Other Comprehensive Income (Loss) [Member] |
Beginning Balance at Dec. 31, 2020 | $ 888,733 | $ 565,112 | $ 336,523 | $ (12,902) | $ 835,184 | $ 319,506 | $ 528,580 | $ (12,902) | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | |||||||||
Comprehensive income (loss) | 80,164 | 0 | 78,666 | 1,498 | $ 82,670 | 82,670 | 0 | 81,172 | 1,498 |
Dividends on common stock | (59,410) | 0 | (59,410) | 0 | (56,056) | 0 | (56,056) | 0 | |
Shares issued in connection with business combinations | 0 | ||||||||
Stock-based compensation | 3,615 | 3,615 | 0 | 0 | |||||
Shares issued pursuant to equity based plans | 4,543 | 4,543 | 0 | 0 | |||||
Capital contributions from parent | 116,009 | 116,009 | 116,009 | 0 | 0 | ||||
Issuance of common stock, net of issuance costs | 17,501 | 17,501 | 0 | 0 | |||||
Ending Balance at Dec. 31, 2021 | $ 935,146 | 590,771 | 355,779 | (11,404) | 977,807 | 435,515 | 553,696 | (11,404) | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | |||||||||
Dividends on common stock (in dollars per share) | $ 1.92 | ||||||||
Comprehensive income (loss) | $ 91,422 | 0 | 86,303 | 5,119 | 96,554 | 96,554 | 0 | 91,564 | 4,990 |
Dividends on common stock | (65,609) | 0 | (65,609) | 0 | (62,667) | 0 | (62,667) | 0 | |
Shares issued in connection with business combinations | 0 | ||||||||
Stock-based compensation | 3,228 | 3,228 | 0 | 0 | |||||
Shares issued pursuant to equity based plans | 2,978 | 2,978 | 0 | 0 | |||||
Capital contributions from parent | 179,388 | 179,388 | 179,388 | 0 | 0 | ||||
Issuance of common stock, net of issuance costs | 208,276 | 208,276 | 0 | 0 | |||||
Ending Balance at Dec. 31, 2022 | $ 1,175,441 | 805,253 | 376,473 | (6,285) | 1,191,082 | 614,903 | 582,593 | (6,414) | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | |||||||||
Dividends on common stock (in dollars per share) | $ 1.93 | ||||||||
Comprehensive income (loss) | $ 93,104 | 0 | 93,868 | (764) | 103,914 | 103,914 | 0 | 104,737 | (823) |
Dividends on common stock | (70,430) | 0 | (70,430) | 0 | (92,376) | 0 | (92,376) | 0 | |
Shares issued in connection with business combinations | 12,884 | 12,884 | 0 | 0 | |||||
Stock-based compensation | 3,598 | 3,598 | 0 | 0 | |||||
Shares issued pursuant to equity based plans | 2,328 | 2,328 | 0 | 0 | |||||
Capital contributions from parent | $ 30,000 | 30,000 | 30,000 | 0 | 0 | ||||
Issuance of common stock, net of issuance costs | 66,913 | 66,913 | 0 | 0 | |||||
Ending Balance at Dec. 31, 2023 | $ 1,283,838 | $ 890,976 | $ 399,911 | $ (7,049) | $ 1,232,620 | $ 644,903 | $ 594,954 | $ (7,237) | |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | |||||||||
Dividends on common stock (in dollars per share) | $ 1.94 |
Consolidated Statement of Cash
Consolidated Statement of Cash Flows - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Operating activities: | |||
Net income | $ 93,868 | $ 86,303 | $ 78,666 |
Adjustments to reconcile net income to cash provided by operations: | |||
Depreciation | 125,581 | 116,707 | 113,534 |
Regulatory amortization of gas reserves | 3,217 | 5,589 | 13,897 |
Deferred income taxes | 8,966 | 17,410 | 14,617 |
Qualified defined benefit pension plan (benefit) expense | (2,430) | 5,351 | 16,556 |
Contributions to qualified defined benefit pension plans | 0 | 0 | (9,590) |
Deferred environmental expenditures, net | (26,052) | (18,160) | (18,187) |
Environmental remediation expense | 12,899 | 12,389 | 9,938 |
Asset optimization revenue sharing bill credits | (10,471) | (41,102) | (9,053) |
Other | 22,972 | 21,558 | 20,622 |
Changes in assets and liabilities: | |||
Receivables, net | 50,977 | (76,454) | (44,128) |
Inventories | (24,105) | (29,269) | (14,571) |
Income and other taxes | (1,246) | 6,908 | 3,292 |
Accounts payable | (39,958) | 24,508 | 12,118 |
Deferred gas costs | 52,371 | 12,334 | (40,541) |
Asset optimization revenue sharing | 22,637 | 28,937 | 44,458 |
Decoupling mechanism | (11,415) | 10,922 | (5,206) |
Cloud-based software | (16,307) | (23,908) | (7,407) |
Other, net | 18,445 | (12,351) | (18,662) |
Cash provided by operating activities | 279,949 | 147,672 | 160,353 |
Investing activities: | |||
Capital expenditures | (327,347) | (338,602) | (293,892) |
Acquisitions, net of cash acquired | (7,533) | (94,279) | (1,289) |
Purchase of equity method investment | (1,000) | (1,000) | (14,450) |
Proceeds from Sale of Equity Method Investments | 0 | 0 | 7,000 |
Other | 383 | (1,579) | 2,508 |
Net Cash Provided by (Used in) Investing Activities, Total | (335,497) | (435,460) | (300,123) |
Financing activities: | |||
Proceeds from common stock issued, net | 66,495 | 208,561 | 17,501 |
Long-term debt issued | 330,000 | 290,000 | 185,000 |
Long-term debt retired | (90,000) | 0 | (95,000) |
Proceeds from term loan due within one year | 0 | 0 | 100,000 |
Repayments of Short-term Debt | 0 | 0 | (100,000) |
Repayments of commercial paper, maturities greater than three months | 0 | 0 | (195,025) |
Changes in other short-term debt, net | (168,540) | (131,300) | 280,000 |
Cash dividend payments on common stock | (67,340) | (62,771) | (55,919) |
Payments of Financing Fees | 2,200 | 912 | 3,899 |
Other | (4,207) | (1,946) | (1,222) |
Cash provided by financing activities | 64,208 | 301,632 | 131,436 |
Increase (decrease) in cash, cash equivalents and restricted cash | 8,660 | 13,844 | (8,334) |
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 49,624 | 40,964 | 27,120 |
Supplemental disclosure of cash flow information: | |||
Interest paid, net of capitalization | 80,197 | 50,823 | 43,719 |
Income taxes paid, net of refunds | 24,263 | 2,779 | 10,555 |
Non-cash activities | |||
Shares issued in connection with business combinations | 12,884 | 0 | 0 |
Debt assumed in connection with business combinations | 3,131 | 0 | 0 |
Northwest Natural Gas Company [Member] | |||
Operating activities: | |||
Net income | 104,737 | 91,564 | 81,172 |
Adjustments to reconcile net income to cash provided by operations: | |||
Depreciation | 119,514 | 112,957 | 110,504 |
Regulatory amortization of gas reserves | 3,217 | 5,589 | 13,897 |
Deferred income taxes | 2,855 | 16,288 | 13,223 |
Qualified defined benefit pension plan (benefit) expense | (2,430) | 5,351 | 16,556 |
Contributions to qualified defined benefit pension plans | 0 | 0 | (9,590) |
Deferred environmental expenditures, net | (26,052) | (18,160) | (18,187) |
Environmental remediation expense | 12,899 | 12,389 | 9,938 |
Asset optimization revenue sharing bill credits | (10,471) | (41,102) | (9,053) |
Other | 22,341 | 20,448 | 18,517 |
Changes in assets and liabilities: | |||
Receivables, net | 51,391 | (75,177) | (43,030) |
Inventories | (23,884) | (28,890) | (14,427) |
Income and other taxes | 4,124 | 6,729 | (10,405) |
Accounts payable | (43,531) | 21,375 | 8,728 |
Deferred gas costs | 52,371 | 12,334 | (40,541) |
Asset optimization revenue sharing | 22,637 | 28,937 | 44,458 |
Decoupling mechanism | (11,415) | 10,922 | (5,206) |
Cloud-based software | (16,307) | (23,908) | (7,407) |
Other, net | 19,872 | (12,455) | (17,653) |
Cash provided by operating activities | 281,868 | 145,191 | 141,494 |
Investing activities: | |||
Capital expenditures | (290,845) | (318,686) | (278,237) |
Other | 384 | (1,579) | 2,508 |
Net Cash Provided by (Used in) Investing Activities, Total | (290,461) | (320,265) | (275,729) |
Financing activities: | |||
Long-term debt issued | 330,000 | 140,000 | 130,000 |
Long-term debt retired | (90,000) | 0 | (60,000) |
Proceeds from term loan due within one year | 0 | 0 | 100,000 |
Repayments of Short-term Debt | 0 | 0 | (100,000) |
Repayments of commercial paper, maturities greater than three months | 0 | 0 | (195,025) |
Changes in other short-term debt, net | (153,420) | (75,300) | 209,000 |
Cash contributions received from parent | 30,000 | 179,388 | 116,009 |
Cash dividend payments on common stock | (92,376) | (62,667) | (56,056) |
Payments of Financing Fees | 2,080 | 843 | 2,818 |
Other | (1,682) | (1,665) | (1,782) |
Cash provided by financing activities | 20,442 | 178,913 | 139,328 |
Increase (decrease) in cash, cash equivalents and restricted cash | 11,849 | 3,839 | 5,093 |
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 36,520 | 24,671 | 20,832 |
Supplemental disclosure of cash flow information: | |||
Interest paid, net of capitalization | 64,054 | 44,813 | 42,395 |
Income taxes paid, net of refunds | $ 27,745 | $ 5,990 | $ 26,451 |
Pension and Other Postretiremen
Pension and Other Postretirement Benefits Costs - Schedule of Fair Value of Plan Assets - Pension Plan [Member] - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | $ 283,443 | $ 280,306 |
Northwest Natural Gas Company [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 283,444 | 280,304 |
Total Pension Asset Investments Net Of Receivables And Payables | 283,443 | 280,304 |
Accrued interest and dividend income | 10,698 | 7,703 |
Total receivables | 10,698 | 7,703 |
Due to broker for securities purchased | (10,698) | (7,701) |
Northwest Natural Gas Company [Member] | United States Equity [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 73,910 | 68,729 |
Northwest Natural Gas Company [Member] | Non-U.S. equity [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 91,497 | 90,504 |
Northwest Natural Gas Company [Member] | Liability hedging [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 98,408 | 94,823 |
Northwest Natural Gas Company [Member] | Opportunistic [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 17,148 | 23,903 |
Northwest Natural Gas Company [Member] | Cash and Cash Equivalents [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 2,480 | 2,345 |
Northwest Natural Gas Company [Member] | Level 1 [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Total Pension Asset Investments Net Of Receivables And Payables | 27,730 | 26,677 |
Northwest Natural Gas Company [Member] | Level 1 [Member] | United States Equity [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 1 [Member] | Non-U.S. equity [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 27,730 | 26,677 |
Northwest Natural Gas Company [Member] | Level 1 [Member] | Liability hedging [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 1 [Member] | Opportunistic [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 1 [Member] | Cash and Cash Equivalents [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 2 [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Total Pension Asset Investments Net Of Receivables And Payables | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 2 [Member] | United States Equity [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 2 [Member] | Non-U.S. equity [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 2 [Member] | Liability hedging [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 2 [Member] | Opportunistic [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 2 [Member] | Cash and Cash Equivalents [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 3 [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Total Pension Asset Investments Net Of Receivables And Payables | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 3 [Member] | United States Equity [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 3 [Member] | Non-U.S. equity [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 3 [Member] | Liability hedging [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 3 [Member] | Opportunistic [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Level 3 [Member] | Cash and Cash Equivalents [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 0 | 0 |
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Total Pension Asset Investments Net Of Receivables And Payables | 255,713 | 253,627 |
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member] | United States Equity [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 73,910 | 68,729 |
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member] | Non-U.S. equity [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 63,767 | 63,827 |
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member] | Liability hedging [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 98,408 | 94,823 |
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member] | Opportunistic [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | 17,148 | 23,903 |
Northwest Natural Gas Company [Member] | Fair Value Measured at NAV [Member] | Cash and Cash Equivalents [Member] | ||
Defined Benefit Plan, Information about Plan Assets [Abstract] | ||
Plan Assets, Amount | $ 2,480 | $ 2,345 |
Organization and Principles of
Organization and Principles of Consolidation | 12 Months Ended |
Dec. 31, 2023 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] | ORGANIZATION AND PRINCIPLES OF CONSOLIDATION The accompanying consolidated financial statements represent the respective, consolidated financial results of NW Holdings and NW Natural and all respective companies that each registrant directly or indirectly controls, either through majority ownership or otherwise. This is a combined report of NW Holdings and NW Natural, which includes separate consolidated financial statements for each registrant. NW Natural's regulated natural gas distribution activities are reported in the natural gas distribution (NGD) segment. The NGD segment is NW Natural's core operating business and serves residential, commercial, and industrial customers in Oregon and southwest Washington. The NGD segment is the only reportable segment for NW Holdings and NW Natural. All other activities, water, wastewater and water services businesses, and other investments are aggregated and reported as other at their respective registrant. NW Holdings and NW Natural consolidate all entities in which they have a controlling financial interest. Investments in corporate joint ventures and partnerships that NW Holdings does not directly or indirectly control, and for which it is not the primary beneficiary, include NNG Financial's investment in Kelso-Beaver Pipeline and NWN Water's investment in Avion Water Company, Inc., which are accounted for under the equity method. NW Natural RNG Holding Company, LLC holds investments in Lexington Renewable Energy, LLC and Dakota City Renewable Energy LLC, which are also accounted for under the equity method. See Note 13 for activity related to equity method investments. NW Holdings and its direct and indirect subsidiaries are collectively referred to herein as NW Holdings, and NW Natural and its direct and indirect subsidiaries are collectively referred to herein as NW Natural. The consolidated financial statements of NW Holdings and NW Natural are presented after elimination of all intercompany balances and transactions. Notes to the consolidated financial statements reflect the activity of continuing operations for both NW Holdings and NW Natural for all periods presented, unless otherwise noted. Certain reclassifications have been made to conform prior period information to the current presentation. The reclassifications did not have a material effect on our consolidated financial statements. |
Earnings Per Share
Earnings Per Share | 12 Months Ended |
Dec. 31, 2023 | |
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] | |
Earnings Per Share [Text Block] | EARNINGS PER SHARE Basic earnings or loss per share are computed using NW Holdings' net income or loss and the weighted average number of common shares outstanding for each period presented. Diluted earnings per share are computed in the same manner, except using the weighted average number of common shares outstanding plus the effects of the assumed exercise of stock options and the payment of estimated stock awards from other stock-based compensation plans that are outstanding at the end of each period presented. Anti-dilutive stock awards are excluded from the calculation of diluted earnings or loss per common share. NW Holdings' diluted earnings or loss per share are calculated as follows: In thousands, except per share data 2023 2022 2021 Net income $ 93,868 $ 86,303 $ 78,666 Average common shares outstanding - basic 36,213 33,934 30,702 Additional shares for stock-based compensation plans (See Note 8) 52 50 50 Average common shares outstanding - diluted 36,265 33,984 30,752 Earnings per share of common stock: Basic $ 2.59 $ 2.54 $ 2.56 Diluted 2.59 2.54 2.56 Additional information: Anti-dilutive shares 1 2 7 |
Segment Information
Segment Information | 12 Months Ended |
Dec. 31, 2023 | |
Segment Reporting [Abstract] | |
Segment Information | SEGMENT INFORMATION We primarily operate in one reportable business segment, which is NW Natural's local gas distribution business and is referred to as the NGD segment. NW Natural and NW Holdings also have investments and business activities not specifically related to the NGD segment, which are aggregated and reported as other and described below for each entity. No individual customer accounts for over 10% of NW Holdings' or NW Natural's operating revenues. Natural Gas Distribution NW Natural's local gas distribution segment (NGD) is a regulated utility principally engaged in the purchase, sale, and delivery of natural gas and related services to customers in Oregon and southwest Washington. The NGD business is responsible for building and maintaining a safe and reliable pipeline distribution system, purchasing sufficient gas supplies from producers and marketers, contracting for firm and interruptible transportation of gas over interstate pipelines to bring gas from the supply basins into its service territory, and re-selling the gas to customers subject to rates, terms, and conditions approved by the OPUC or WUTC. NGD also includes taking customer-owned gas and transporting it from interstate pipeline connections, or city gates, to the customers’ end-use facilities for a fee, which is approved by the OPUC or WUTC. Approximately 88% of NGD customers are located in Oregon and 12% in Washington. On an annual basis, residential and commercial customers typically account for around 60% of total NGD volumes delivered and around 90% of NGD margin. Industrial customers largely account for the remaining volumes and NGD margin. A small amount of the margin is also derived from miscellaneous services, gains or losses from an incentive gas cost sharing mechanism, and other service fees. Industrial sectors served by the NGD business include: pulp, paper, and other forest products; the manufacture of electronic, electrochemical and electrometallurgical products; the processing of farm and food products; the production of various mineral products; metal fabrication and casting; the production of machine tools, machinery, and textiles; the manufacture of asphalt, concrete, and rubber; printing and publishing; nurseries; and government and educational institutions. In addition to NW Natural's local gas distribution business, the NGD segment also includes the portion of the Mist underground storage facility used to serve NGD customers, North Mist gas storage, NWN Gas Reserves, which is a wholly-owned subsidiary of Energy Corp, and NW Natural RNG Holding Company, LLC, a holding company established to invest in the development and procurement of regulated renewable natural gas for NW Natural. NW Natural NW Natural's activities in Other include Interstate Storage Services and third-party asset management services for the Mist facility in Oregon, appliance retail center operations, and corporate operating and non-operating revenues and expenses that cannot be allocated to NGD operations. Earnings from Interstate Storage Services assets are primarily related to firm storage capacity revenues. Earnings from the Mist facility also include revenue, net of amounts shared with NGD customers, from management of NGD assets at Mist and upstream pipeline capacity when not needed to serve NGD customers. Under the Oregon sharing mechanism, NW Natural retains 80% of the pre-tax income from these services when the costs of the capacity were not included in NGD rates, or 10% of the pre-tax income when the costs have been included in these rates. The remaining 20% and 90%, respectively, are recorded to a deferred regulatory account for crediting back to NGD customers. NW Holdings NW Holdings' activities in Other include all remaining activities not associated with NW Natural, specifically NWN Water, which consolidates the water and wastewater utility operations and water services businesses; NWN Water's equity investment in Avion Water Company, Inc.; NWN Gas Storage, a wholly-owned subsidiary of NWN Energy; other pipeline assets in NNG Financial; and NW Natural Renewables Holdings, LLC and its non-regulated renewable natural gas activities. Other also includes corporate revenues and expenses that cannot be allocated to other operations, including certain business development activities. Segment Information Summary Inter-segment transactions were immaterial for the periods presented. The following table presents summary financial information concerning the reportable segment and other operations. In thousands NGD Other NW Natural Other NW Holdings 2023 Operating revenues $ 1,136,400 $ 22,223 $ 1,158,623 $ 38,852 $ 1,197,475 Depreciation 118,417 1,097 119,514 6,067 125,581 Income (loss) from operations 170,591 15,054 185,645 (704) 184,941 Net income (loss) 94,042 10,695 104,737 (10,869) 93,868 Capital expenditures 285,998 4,847 290,845 36,502 327,347 Total assets at December 31, 2023 4,458,117 53,260 4,511,377 355,715 4,867,092 2022 Operating revenues $ 989,752 $ 24,587 $ 1,014,339 $ 23,014 $ 1,037,353 Depreciation 111,871 1,086 112,957 3,750 116,707 Income (loss) from operations 152,839 16,535 169,374 (1,897) 167,477 Net income (loss) 79,690 11,874 91,564 (5,261) 86,303 Capital expenditures 315,979 2,707 318,686 19,916 338,602 Total assets at December 31, 2022 4,392,699 60,019 4,452,718 295,608 4,748,326 2021 Operating revenues $ 816,887 $ 26,170 $ 843,057 $ 17,343 $ 860,400 Depreciation 109,475 1,029 110,504 3,030 113,534 Income (loss) from operations 147,902 17,331 165,233 (2,116) 163,117 Net income (loss) 68,988 12,184 81,172 (2,506) 78,666 Capital expenditures 275,267 2,970 278,237 15,655 293,892 Total assets at December 31, 2021 3,846,112 52,260 3,898,372 166,232 4,064,604 Natural Gas Distribution Margin NGD margin is the primary financial measure used by the CODM, consisting of NGD operating revenues, reduced by the associated cost of gas, environmental remediation expense, and revenue taxes. The cost of gas purchased for NGD customers is generally a pass-through cost in the amount of revenues billed to regulated NGD customers. Environmental remediation expense represents collections received from customers through environmental recovery mechanisms in Oregon and Washington as well as adjustments for the Oregon environmental earnings test when applicable. This is offset by environmental remediation expense presented in operating expenses. Revenue taxes are collected from NGD customers and remitted to taxing authorities. The collections from customers are offset by the expense recognition of the obligation to the taxing authority. By subtracting cost of gas, environmental remediation expense, and revenue taxes from NGD operating revenues, NGD margin provides a key metric used by the CODM in assessing the performance of the NGD segment. The following table presents additional segment information concerning NGD margin: In thousands 2023 2022 2021 NGD margin calculation: NGD operating revenues $ 1,117,498 $ 970,124 $ 797,800 Other regulated services 18,902 19,628 19,087 Total NGD operating revenues 1,136,400 989,752 816,887 Less: NGD cost of gas 500,061 429,861 292,538 Environmental remediation expense 12,899 12,389 9,938 Revenue taxes 48,432 41,627 34,600 NGD margin $ 575,008 $ 505,875 $ 479,811 |
Revenue Revenue
Revenue Revenue | 12 Months Ended |
Dec. 31, 2023 | |
Revenue from Contract with Customer [Abstract] | |
Revenue | REVENUE The following table presents disaggregated revenue from continuing operations: Year ended December 31, 2023 In thousands NGD Other NW Natural Other NW Holdings Natural gas sales $ 1,109,223 $ — $ 1,109,223 $ — $ 1,109,223 Gas storage revenue, net — 12,041 12,041 — 12,041 Asset management revenue, net — 5,942 5,942 — 5,942 Appliance retail center revenue — 4,240 4,240 — 4,240 Other revenue 2,929 — 2,929 38,852 41,781 Revenue from contracts with customers 1,112,152 22,223 1,134,375 38,852 1,173,227 Alternative revenue 8,198 — 8,198 — 8,198 Leasing revenue 16,050 — 16,050 — 16,050 Total operating revenues $ 1,136,400 $ 22,223 $ 1,158,623 $ 38,852 $ 1,197,475 Year ended December 31, 2022 In thousands NGD Other NW Natural Other NW Holdings Natural gas sales $ 989,654 $ — $ 989,654 $ — $ 989,654 Gas storage revenue, net — 11,792 11,792 — 11,792 Asset management revenue, net — 6,965 6,965 — 6,965 Appliance retail center revenue — 5,830 5,830 — 5,830 Other revenue 2,510 — 2,510 23,014 25,524 Revenue from contracts with customers 992,164 24,587 1,016,751 23,014 1,039,765 Alternative revenue (19,605) — (19,605) — (19,605) Leasing revenue 17,193 — 17,193 — 17,193 Total operating revenues $ 989,752 $ 24,587 $ 1,014,339 $ 23,014 $ 1,037,353 Year ended December 31, 2021 In thousands NGD Other NW Natural Other NW Holdings Natural gas sales $ 783,027 $ — $ 783,027 $ — $ 783,027 Gas storage revenue, net — 10,830 10,830 — 10,830 Asset management revenue, net — 9,387 9,387 — 9,387 Appliance retail center revenue — 5,953 5,953 — 5,953 Other revenue 1,615 — 1,615 17,343 18,958 Revenue from contracts with customers 784,642 26,170 810,812 17,343 828,155 Alternative revenue 14,694 — 14,694 — 14,694 Leasing revenue 17,551 — 17,551 — 17,551 Total operating revenues $ 816,887 $ 26,170 $ 843,057 $ 17,343 $ 860,400 NW Natural's revenue represents substantially all of NW Holdings' revenue and is recognized for both registrants when the obligation to customers is satisfied and in the amount expected to be received in exchange for transferring goods or providing services. Revenue from contracts with customers contains one performance obligation that is generally satisfied over time, using the output method based on time elapsed, due to the continuous nature of the service provided. The transaction price is determined by a set price agreed upon in the contract or dependent on regulatory tariffs. Customer accounts are settled on a monthly basis or paid at time of sale and based on historical experience. It is probable that we will collect substantially all of the consideration to which we are entitled. We evaluated the probability of collection in accordance with the current expected credit losses standard. NW Holdings and NW Natural do not have any material contract assets, as net accounts receivable and accrued unbilled revenue balances are unconditional and only involve the passage of time until such balances are billed and collected. NW Holdings and NW Natural do not have any material contract liabilities. Revenue taxes are included in operating revenues with an equal and offsetting expense recognized in operating expenses in the consolidated statements of comprehensive income. Revenue-based taxes are primarily franchise taxes, which are collected from NGD customers and remitted to taxing authorities. Natural Gas Distribution Natural Gas Sales NW Natural's primary source of revenue is providing natural gas to customers in the NGD service territory, which includes residential, commercial, industrial and transportation customers. NGD revenue is generally recognized over time upon delivery of the gas commodity or service to the customer, and the amount of consideration received and recognized as revenue is dependent on the Oregon and Washington tariffs. Customer accounts are to be paid in full each month, and there is no right of return or warranty for services provided. Revenues include firm and interruptible sales and transportation services, franchise taxes recovered from the customer, late payment fees, service fees, and accruals for gas delivered but not yet billed (accrued unbilled revenue). The accrued unbilled revenue balance is based on estimates of deliveries during the period from the last meter reading and management judgment is required for a number of factors used in this calculation, including customer use and weather factors. We applied the significant financing practical expedient and have not adjusted the consideration NW Natural expects to receive from NGD customers for the effects of a significant financing component as all payment arrangements are settled annually. Due to the election of the right to invoice practical expedient, we do not disclose the value of unsatisfied performance obligations. Alternative Revenue Weather normalization (WARM) and decoupling mechanisms are considered to be alternative revenue programs. Alternative revenue programs are considered to be contracts between NW Natural and its regulator and are excluded from revenue from contracts with customers. Leasing Revenue Leasing revenue primarily consists of revenues from NW Natural's North Mist Storage contract with Portland General Electric (PGE) in support of PGE's gas-fired electric power generation facilities under an initial 30-year contract with options to extend, totaling up to an additional 50 years upon mutual agreement of the parties. The facility is accounted for as a sales-type lease with regulatory accounting deferral treatment. The investment is included in rate base under an established cost-of-service tariff schedule, with revenues recognized according to the tariff schedule and as such, profit upon commencement was deferred and will be amortized over the lease term. Leasing revenue also contains rental revenue from small leases of property owned by NW Natural to third parties. The majority of these transactions are accounted for as operating leases and the revenue is recognized over the term of the lease agreement. Lease revenue is excluded from revenue from contracts with customers. See Note 7 for additional information. NW Natural Other Gas Storage Revenue NW Natural's other revenue includes gas storage activity, which includes Interstate Storage Services used to store natural gas for customers. Gas storage revenue is generally recognized over time as the gas storage service is provided to the customer and the amount of consideration received and recognized as revenue is dependent on set rates defined per the storage agreements. Noncash consideration in the form of dekatherms of natural gas is received as consideration for providing gas injection services to gas storage customers. This noncash consideration is measured at fair value using the average spot rate. Customer accounts are generally paid in full each month, and there is no right of return or warranty for services provided. Revenues include firm and interruptible storage services, net of the profit sharing amount refunded to NGD customers. Asset Management Revenue Revenues include the optimization of storage assets and pipeline capacity and are provided net of the profit sharing amount refunded to NGD customers. Certain asset management revenues received are recognized over time using a straight-line approach over the term of each contract, and the amount of consideration received and recognized as revenue is dependent on a variable pricing model. Variable revenues earned above guaranteed amounts are estimated and recognized at the end of each period using the most likely amount approach. Additionally, other asset management revenues may be based on a fixed rate. Generally, asset management accounts are settled on a monthly basis. As of December 31, 2023, unrecognized revenue for the fixed component of the transaction price related to gas storage and asset management revenue was approximately $78.1 million. Of this amount, approximately $19.9 million will be recognized in 2024, $19.0 million in 2025, $14.9 million in 2026, $7.4 million in 2027, and $16.9 million thereafter. The amounts presented here are calculated using current contracted rates. Appliance Retail Center Revenue NW Natural owns and operates an appliance store that is open to the public, where customers can purchase natural gas home appliances. Revenue from the sale of appliances is recognized at the point in time in which the appliance is transferred to the third party responsible for delivery and installation services and when the customer has legal title to the appliance. It is required that the sale be paid for in full prior to transfer of legal title. The amount of consideration received and recognized as revenue varies with changes in marketing incentives and discounts offered to customers. NW Holdings Other NW Holdings' primary source of other revenue is providing water and wastewater services to customers. Water and wastewater service revenue is generally recognized over time upon delivery of the water commodity or service to the customer, and the amount of consideration received and recognized as revenue is dependent on the tariffs established in the state we operate. Customer accounts are to be paid in full each month, and there is no right of return or warranty for services provided. |
Leases (Notes)
Leases (Notes) | 12 Months Ended |
Dec. 31, 2023 | |
Leases [Abstract] | |
Lessee, Operating Leases | LEASES Lease Revenue Leasing revenue primarily consists of NW Natural's North Mist natural gas storage agreement with PGE which is billed under an OPUC-approved rate schedule and includes an initial 30-year term beginning May 2019 with options to extend, totaling up to an additional 50 years upon mutual agreement of the parties. Under U.S. GAAP, this agreement is classified as a sales-type lease and qualifies for regulatory accounting deferral treatment. The investment in the storage facility is included in rate base under a separately established cost-of-service tariff, with revenues recognized according to the tariff schedule. As such, the selling profit that was calculated upon commencement as part of the sale-type lease recognition was deferred and will be amortized over the lease term. Billing rates under the cost-of-service tariff will be updated annually to reflect current information including depreciable asset levels, forecasted operating expenses, and the results of regulatory proceedings, as applicable, and revenue received under this agreement is recognized as operating revenue on the consolidated statements of comprehensive income. There are no variable payments or residual value guarantees. The lease does not contain an option to purchase the underlying assets. NW Natural also maintains a sales-type lease for specialized compressor facilities to provide high pressure compressed natural gas (CNG) services. Lease payments are outlined in an OPUC-approved rate schedule over a 10-year term. There are no variable payments or residual value guarantees. The selling profit computed upon lease commencement was not significant. Our lessor portfolio also contains small leases of property owned by NW Natural to third parties. These transactions are accounted for as operating leases and the revenue is recognized over the term of the lease agreement. The components of lease revenue at NW Natural were as follows: Year ended December 31, In thousands 2023 2022 2021 Lease revenue Operating leases $ 76 $ 74 $ 80 Sales-type leases 15,974 17,119 17,471 Total lease revenue $ 16,050 $ 17,193 $ 17,551 Additionally, lease revenue of $0.6 million, $0.6 million and $0.5 million was recognized for each of the years ended December 31, 2023, 2022, and 2021, respectively, related to operating leases associated with non-utility property rentals. Lease revenue related to these leases was presented in other income (expense), net on the consolidated statements of comprehensive income as it is non-operating income. Total future minimum lease payments to be received under non-cancelable leases at December 31, 2023 are as follows: In thousands Operating Sales-Type Total NW Natural: 2024 $ 603 $ 15,867 $ 16,470 2025 599 15,306 15,905 2026 36 14,901 14,937 2027 22 14,521 14,543 2028 — 13,983 13,983 Thereafter — 208,316 208,316 Total minimum lease payments $ 1,260 282,894 $ 284,154 Less: imputed interest 153,806 Total leases receivable $ 129,088 Other NW Holdings: 2024 $ 52 $ — $ 52 2025 53 — 53 2026 56 — 56 2027 57 — 57 2028 58 — 58 Thereafter 800 — 800 Total minimum lease payments $ 1,076 $ — $ 1,076 NW Holdings: 2024 $ 655 $ 15,867 $ 16,522 2025 652 15,306 15,958 2026 92 14,901 14,993 2027 79 14,521 14,600 2028 58 13,983 14,041 Thereafter 800 208,316 209,116 Total minimum lease payments $ 2,336 282,894 $ 285,230 Less: imputed interest 153,806 Total leases receivable $ 129,088 The total leases receivable above is reported under the NGD segment and the short- and long-term portions are included within other current assets and assets under sales-type leases on the consolidated balance sheets, respectively. The total amount of unguaranteed residual assets was $5.5 million and $5.1 million at December 31, 2023 and 2022, respectively, and is included in assets under sales-type leases on the consolidated balance sheets. Additionally, under regulatory accounting, the revenues and expenses associated with these agreements are presented on the consolidated statements of comprehensive income such that their presentation aligns with similar regulated activities at NW Natural. Lease Expense Operating Leases We have operating leases for land, buildings and equipment. Our primary lease is for NW Natural's headquarters and operations center. Our leases have remaining lease terms of nine months to 16 years. Many of our lease agreements include options to extend the lease, which we do not include in our minimum lease terms unless they are reasonably certain to be exercised. Short-term leases with a term of 12 months or less are not recorded on the balance sheet. As most of our leases do not provide an implicit rate and are entered into by NW Natural, we use an estimated discount rate representing the rate we would have incurred to finance the funds necessary to purchase the leased asset and is based on information available at the lease commencement date in determining the present value of lease payments. The components of lease expense, a portion of which is capitalized, were as follows: Year ended December 31, 2023 In thousands NW Natural Other NW Holdings Operating lease expense $ 7,244 $ 176 $ 7,420 Short-term lease expense 925 — 925 Year ended December 31, 2022 In thousands NW Natural Other NW Holdings Operating lease expense $ 7,003 $ 31 $ 7,034 Short-term lease expense 880 — 880 Year ended December 31, 2021 In thousands NW Natural Other NW Holdings Operating lease expense $ 6,859 $ 58 $ 6,917 Short-term lease expense 1,220 — 1,220 Supplemental balance sheet information related to operating leases as of December 31, 2023 is as follows: In thousands NW Natural Other NW Holdings Operating lease right of use assets $ 70,728 $ 580 $ 71,308 Operating lease liabilities - current liabilities $ 2,128 $ 205 $ 2,333 Operating lease liabilities - non-current liabilities 76,757 410 77,167 Total operating lease liabilities $ 78,885 $ 615 $ 79,500 Supplemental balance sheet information related to operating leases as of December 31, 2022 is as follows: In thousands NW Natural Other NW Holdings Operating lease right of use assets $ 72,720 $ 709 $ 73,429 Operating lease liabilities - current liabilities $ 1,363 $ 151 $ 1,514 Operating lease liabilities - non-current liabilities 78,345 620 78,965 Total operating lease liabilities $ 79,708 $ 771 $ 80,479 The weighted-average remaining lease terms and weighted-average discount rates for the operating leases at NW Natural were as follows: 2023 2022 Weighted-average remaining lease term (years) 16.2 17.2 Weighted-average discount rate 7.3 % 7.3 % Headquarters and Operations Center Lease NW Natural commenced a 20-year operating lease agreement in March 2020 for a new headquarters and operations center in Portland, Oregon. There is an option to extend the term of the lease for two additional periods of seven years. There is a material timing difference between the minimum lease payments and expense recognition as calculated under operating lease accounting rules. OPUC issued an order allowing us to align our expense recognition with cash payments for ratemaking purposes. We recorded the difference between the minimum lease payments and the aggregate of the imputed interest on the finance lease obligation and amortization of the right-of-use asset as a regulatory asset on our balance sheet. The balance of the regulatory asset was $8.0 million and $6.9 million as of December 31, 2023 and 2022, respectively. Maturities of operating lease liabilities at December 31, 2023 were as follows: In thousands NW Natural Other NW Holdings 2024 $ 7,484 $ 183 $ 7,667 2025 7,362 176 7,538 2026 7,361 153 7,514 2027 7,538 107 7,645 2028 7,719 6 7,725 Thereafter 101,272 6 101,278 Total lease payments 138,736 631 139,367 Less: imputed interest 59,851 16 59,867 Total lease obligations 78,885 615 79,500 Less: current obligations 2,128 205 2,333 Long-term lease obligations $ 76,757 $ 410 $ 77,167 As of December 31, 2023, there were no finance lease liabilities at NW Natural. Cash Flow Information Supplemental cash flow information related to leases was as follows: Year ended December 31, 2023 In thousands NW Natural Other NW Holdings Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 7,434 $ 176 $ 7,610 Finance cash flows from finance leases 369 — 369 Right of use assets obtained in exchange for lease obligations Operating leases $ 659 $ — $ 659 Finance leases 369 101 470 Year ended December 31, 2022 In thousands NW Natural Other NW Holdings Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 6,993 $ 64 $ 7,057 Finance cash flows from finance leases 524 — 524 Right of use assets obtained in exchange for lease obligations Operating leases $ 309 $ 668 $ 977 Finance leases 270 — 270 Year ended December 31, 2021 In thousands NW Natural Other NW Holdings Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 6,840 $ 58 $ 6,898 Finance cash flows from finance leases 801 — 801 Right of use assets obtained in exchange for lease obligations Operating leases $ 223 $ — $ 223 Finance leases 314 — 314 Finance Leases 2.6 million 2.3 million |
Stock-Based Compensation (Notes
Stock-Based Compensation (Notes) | 12 Months Ended |
Dec. 31, 2023 | |
Share-Based Payment Arrangement [Abstract] | |
Share-based Payment Arrangement [Text Block] | STOCK-BASED COMPENSATION Stock-based compensation plans are designed to promote stock ownership in NW Holdings by employees and officers of NW Holdings and its affiliates. These compensation plans include a Long Term Incentive Plan (LTIP) and an ESPP. Long Term Incentive Plan The LTIP is intended to provide a flexible, competitive compensation program for eligible officers and key employees. Under the LTIP, shares of NW Holdings common stock are authorized for equity incentive grants in the form of stock, restricted stock, restricted stock units, stock options, or performance shares. An aggregate of 1,100,000 shares were authorized for issuance as of December 31, 2023. Shares awarded under the LTIP may be purchased on the open market or issued as original shares. Of the 1,100,000 shares of common stock authorized for LTIP awards at December 31, 2023, there were 180,755 shares available for issuance under any type of award. This assumes market, performance, and service-based grants currently outstanding are awarded at the target level. There were no outstanding grants of restricted stock or stock options under the LTIP at December 31, 2023 or 2022. The LTIP stock awards are compensatory awards for which compensation expense is based on the fair value of stock awards, with expense being recognized over the performance and vesting period of the outstanding awards. Forfeitures are recognized as they occur. Performance Shares LTIP performance shares incorporate a combination of market, performance, and service-based factors. The following table summarizes performance share expense information: Dollars in thousands Shares (1) Expense During Award Year (2) Total Expense for Award Estimated award: 2021-2023 grant (3) 40,719 $ 1,581 $ 1,581 Actual award: 2020-2022 grant 29,472 $ 888 $ 888 2019-2021 grant 37,430 $ 1,323 $ 1,323 (1) In addition to common stock shares, a participant also receives a dividend equivalent cash payment equal to the number of shares of common stock received on the award payout multiplied by the aggregate cash dividends paid per share during the performance period. (2) Amount represents the expense recognized in the third year of the vesting period noted above. For the 2019-2021, 2020-2022, and 2021-2023 grants, mutual understanding of the award's key terms was established in the third year of the vesting period, triggering full expense recognition in 2021, 2022, and 2023, respectively. (3) This represents the estimated number of shares to be awarded as of December 31, 2023 as certain performance share measures have been achieved. Amounts are subject to change with final payout amounts authorized by the Board of Directors in February 2024. The aggregate number of performance shares granted and outstanding at the target and maximum levels were as follows: Dollars in thousands Performance Share Awards Outstanding 2023 Performance Period Target Maximum Expense 2021-23 48,030 96,060 $ 1,581 2022-24 — — — 2023-25 — — — Total 48,030 96,060 $ 1,581 Performance share awards are based on the achievement of a three three Compensation expense is recognized in accordance with accounting standards for stock-based compensation and calculated based on performance levels achieved and an estimated fair value using the Monte-Carlo method. Due to there not being a mutual understanding of the 2022-2024 and 2023-2025 awards' key terms and conditions as noted above, the grant date fair value has not yet been determined and no non-vested shares existed at December 31, 2023. The weighted-average grant date fair value of non-vested shares associated with the 2021-2023 awards was $49.17 per share at December 31, 2023. The weighted-average grant date fair value of shares vested during the year was $49.17 per share and there were no performance shares granted during the year and no unrecognized compensation expense for accounting purposes as of December 31, 2023. Restricted Stock Units In 2012, RSUs began being granted under the LTIP instead of stock options under the Restated SOP. Generally, the RSUs awarded are forfeitable and include a performance-based threshold as well as a vesting period of four years from the grant date. The majority of our RSU grants obligate NW Holdings, upon vesting, to issue the RSU holder one share of common stock. The grant may also include a cash payment equal to the total amount of dividends paid per share between the grant date and vesting date of that portion of the RSU depending on the structure of the award agreement. The fair value of an RSU is equal to the closing market price of NW Holdings' common stock on the grant date. During 2023, total RSU expense was $1.9 million compared to $2.1 million in 2022 and $2.0 million in 2021. As of December 31, 2023, there was $3.1 million of unrecognized compensation cost from grants of RSUs, which is expected to be recognized over a period extending through 2027 . Information regarding the RSU activity is summarized as follows: Number of RSUs Weighted - Nonvested, December 31, 2020 82,464 $ 59.40 Granted 38,160 49.16 Vested (31,733) 60.06 Forfeited (1,164) 46.82 Nonvested, December 31, 2021 87,727 54.87 Granted 48,212 46.50 Vested (33,054) 55.90 Forfeited (3,037) 56.34 Nonvested, December 31, 2022 99,848 50.44 Granted 45,532 48.24 Vested (36,393) 56.65 Forfeited (11,696) 49.98 Nonvested, December 31, 2023 97,291 $ 49.80 Employee Stock Purchase Plan NW Holdings' ESPP allows employees of NW Holdings, NW Natural and certain designated subsidiaries to purchase common stock at 85% of the closing price on the trading day immediately preceding the initial offering date, which is set annually. For the 2023-2024 ESPP period, each eligible employee may purchase up to $21,224 worth of stock through payroll deductions over a period defined by the Board of Directors, with shares issued at the end of the subscription period. Stock-Based Compensation Expense Stock-based compensation expense is recognized as operations and maintenance expense or is capitalized as part of construction overhead at the entity at which the award recipient is employed. The following table summarizes the NW Holdings' financial statement impact, substantially all of which was recorded at NW Natural, of stock-based compensation under the LTIP and ESPP: In thousands 2023 2022 2021 Operations and maintenance expense, for stock-based compensation $ 3,293 $ 2,877 $ 3,272 Income tax benefit (872) (762) (866) Net stock-based compensation effect on net income 2,421 2,115 2,406 Amounts capitalized for stock-based compensation $ 305 $ 351 $ 344 |
Debt
Debt | 12 Months Ended |
Dec. 31, 2023 | |
Debt Disclosure [Abstract] | |
Debt [Text Block] | DEBT Short-Term Debt The primary source of short-term liquidity for NW Holdings is cash balances, dividends from its operating subsidiaries, in particular NW Natural, available cash from a multi-year credit facility, and short-term credit facilities it may enter into from time to time. The primary source of short-term liquidity for NW Natural is from the sale of commercial paper, available cash from a multi-year credit facility, and short-term credit facilities it may enter into from time to time. In addition to issuing commercial paper or entering into bank loans to meet working capital requirements, including seasonal requirements to finance gas purchases and accounts receivable, short-term debt may also be used to temporarily fund capital requirements. For NW Natural, commercial paper and bank loans are periodically refinanced through the sale of long-term debt or equity contributions from NW Holdings. Commercial paper, when outstanding, is sold through two commercial banks under an issuing and paying agency agreement and is supported by one or more unsecured revolving credit facilities. See “ Credit Agreements ” below. At December 31, 2023 and 2022, NW Natural's short-term debt consisted of the following: December 31, 2023 December 31, 2022 In millions Balance Outstanding Weighted Average Interest Rate (1) Balance Outstanding Weighted Average Interest Rate (1) NW Natural: Commercial paper $ 16.8 5.5 % $ 170.2 4.6 % Other (NW Holdings): Credit agreement 73.0 6.4 % 88.0 5.3 % NW Holdings $ 89.8 $ 258.2 (1) Weighted average interest rate on outstanding short-term debt The carrying cost of commercial paper approximates fair value using Level 2 inputs. See Note 2 for a description of the fair value hierarchy. At December 31, 2023, NW Natural's commercial paper had a maximum remaining maturity of 5 days and an average remaining maturity of 4 days. Credit Agreements NW Holdings In November 2021, NW Holdings entered into an amended and restated $200.0 million credit agreement, with a feature that allows NW Holdings to request increases in the total commitment amount, up to a maximum of $300.0 million. The maturity date of the agreement is November 3, 2026, with an available extension of commitments for two additional one The NW Holdings credit agreement permits the issuance of letters of credit in an aggregate amount of up to $40.0 million. The principal amount of borrowings under the credit agreement is due and payable on the maturity date. The credit agreement requires NW Holdings to maintain a consolidated indebtedness to total capitalization ratio of 70% or less. Failure to comply with this covenant would entitle the lenders to terminate their lending commitments and accelerate the maturity of all amounts outstanding. NW Holdings was in compliance with this covenant at December 31, 2023 and 2022. The NW Holdings credit agreement also requires NW Holdings to maintain debt ratings (which are defined by a formula using NW Natural's credit ratings in the event NW Holdings does not have a credit rating) with Standard & Poor's (S&P) and Moody's Investors Service, Inc. (Moody’s) and notify the lenders of any change in its senior unsecured debt ratings or senior secured debt ratings, as applicable, by such rating agencies. A change in NW Holdings' debt ratings by S&P or Moody’s is not an event of default, nor is the maintenance of a specific minimum level of debt rating a condition of drawing upon the credit agreement. Rather, interest rates on any loans outstanding under the credit agreements are tied to debt ratings and therefore, a change in the debt rating would increase or decrease the cost of any loans under the credit agreements when ratings are changed. NW Holdings maintains a credit rating with S&P of A+ and does not currently maintain ratings with Moody's. There was $73.0 million and $88.0 million of outstanding balances under the NW Holdings agreement at December 31, 2023 and 2022, respectively. No letters of credit were issued or outstanding under the NW Holdings agreement at December 31, 2023 and 2022. NW Natural In November 2021, NW Natural entered into an amended and restated credit agreement for unsecured revolving loans totaling $400.0 million, with a feature that allows NW Natural to request increases in the total commitment amount, up to a maximum of $600.0 million. The maturity date of the agreement is November 3, 2026 with an available extension of commitments for two additional one aggregate amount of up to $60.0 million. The principal amount of borrowings under the credit agreement is due and payable on the maturity date. Interest charges on the NW Natural credit agreement were indexed to the LIBOR through January 31, 2023. The agreement was amended to replace LIBOR with the SOFR beginning February 2023. The SOFR is subject to a 10 basis point spread adjustment. NW Natural's credit agreement requires NW Natural to maintain a consolidated indebtedness to total capitalization ratio of 70% or less. Failure to comply with this covenant would entitle the lenders to terminate their lending commitments and accelerate the maturity of all amounts outstanding. NW Natural was in compliance with this covenant at December 31, 2023 and 2022. The NW Natural credit agreement also requires NW Natural to maintain credit ratings with S&P and Moody’s and notify the lenders of any change in NW Natural's senior unsecured debt ratings or senior secured debt ratings, as applicable, by such rating agencies. A change in NW Natural's debt ratings by S&P or Moody’s is not an event of default, nor is the maintenance of a specific minimum level of debt rating a condition of drawing upon the credit agreement. Rather, interest rates on any loans outstanding under the credit agreement are tied to debt ratings and therefore, a change in the debt rating would increase or decrease the cost of any loans under the credit agreement when ratings are changed. There was one letter of credit outstanding at December 31, 2023 under NW Natural's credit agreement and no letters of credit outstanding at December 31, 2022. In December 2023, NW Natural issued a $15 million letter of credit through its existing credit agreement, which expired January 5, 2024. Letters of Credit Facility In January 2024, NW Natural entered into an Uncommitted Letter of Credit and Reimbursement Agreement (LC Reimbursement Agreement), pursuant to which NW Natural agreed to reimburse each Lender acting as an issuing bank (Issuing Bank) thereunder for disbursements in respect of letters of credit (Letters of Credit) issued pursuant to the LC Reimbursement Agreement from time to time. The Company expects to use Letters of Credit issued under the facility created by the LC Reimbursement Agreement (LC Facility) primarily to support its participation in Washington Climate Commitment Act cap-and-invest program auctions. Although there is no expressly stated maximum amount of Letters of Credit that can be issued or outstanding under the LC Facility, under current regulatory authority from the OPUC, the aggregate sum of Letters of Credit outstanding and available to be drawn under the LC Reimbursement Agreement may not exceed $100 million at any one time. The Issuing Banks have no commitment to issue Letters of Credit under the LC Facility and will have the discretion to limit and condition the terms for the issuance of Letters of Credit (including maximum face amounts) in their sole discretion. The LC Reimbursement Agreement requires NW Natural to maintain certain ratings with S&P and Moody’s. NW Natural must also notify the Administrative Agent and Lenders of any change in the S&P or Moody’s Ratings, although any such change is not an event of default. The LC Reimbursement Agreement prohibits NW Natural from permitting Consolidated Indebtedness to be greater than 70% of Total Capitalization, each as defined therein and calculated as of the end of each fiscal quarter of NW Natural. Failure to comply with this financial covenant would constitute an Event of Default under the LC Reimbursement Agreement. The occurrence of this or any other Event of Default would entitle the Administrative Agent to require cash collateral for the LC Exposure, as defined in the LC Reimbursement Agreement, and to exercise all other rights and remedies available to it and the Lenders under the Credit Documents, as defined in the LC Reimbursement Agreement, and under applicable law. Long-Term Debt At December 31, 2023 and 2022, NW Holdings long-term debt consisted of the following: December 31, 2023 December 31, 2022 In millions Balance Outstanding Weighted Average Interest Rate (1) Balance Outstanding Weighted Average Interest Rate (1) NW Natural first mortgage bonds $ 1,374.7 4.7 % $ 1,134.7 4.5 % NW Holdings credit agreement 100.0 5.5 % 100.0 4.2 % NWN Water credit agreement 50.0 5.8 % 50.0 4.2 % NWN Water term loan 55.0 4.7 % 55.0 2.5 % Other long-term debt 6.6 6.2 Long-term debt, gross 1,586.3 1,345.9 Less: unamortized debt issuance costs 10.0 9.0 Less: current maturities 150.9 90.7 Total long-term debt $ 1,425.4 $ 1,246.2 (1) Weighted average interest rate for the years ended December 31, 2023 and 2022. NW Natural Long-Term Debt NW Natural's issuance of First Mortgage Bonds (FMBs), which includes NW Natural's medium-term notes, under the Mortgage and Deed of Trust (Mortgage) is limited by eligible property, adjusted net earnings, and other provisions of the Mortgage. The Mortgage constitutes a first mortgage lien on certain gas properties owned from time to time by NW Natural, including substantially all of NW Natural's NGD property. In August 2023, NW Natural issued and sold $80.0 million aggregate principal amount of its FMBs, 5.18% Series and $50.0 million aggregate principal amount of its FMBs, 5.23% Series. The 5.18% Bonds bear interest at the rate of 5.18% per annum, payable semi-annually on February 4 and August 4 of each year, commencing February 4, 2024, and will mature on August 4, 2034. The 5.23% Bonds bear interest at the rate of 5.23% per annum, payable semi-annually on February 4 and August 4 of each year, commencing February 4, 2024, and will mature on August 4, 2038. In March 2023, NW Natural issued and sold $100.0 million aggregate principal amount of 5.75% Secured Medium-Term Notes, Series B due 2033 (the Notes). The Notes bear interest at the rate of 5.75% per annum, payable semi-annually on March 15 and September 15 of each year. In January 2023, NW Natural issued and sold $100.0 million aggregate principal amount of its FMBs, 5.43% Series due January 2053. The 5.43% Bonds bear interest at the rate of 5.43% per annum, payable semi-annually on January 6 and July 6 of each year, commencing July 6, 2023, and will mature on January 6, 2053. NW Holdings Note Purchase Agreement In December 2023, NW Holdings entered into a Note Purchase Agreement between NW Holdings and the institutional investors named as purchasers therein. The Note Purchase Agreement provides for the issuance of (i) $100.0 million aggregate principal amount of NW Holdings’ 5.78% Senior Notes, Series A, due March 7, 2028 (5.78% Notes) and (ii) $50.0 million aggregate principal amount of NW Holdings’ 5.84% Senior Notes, Series B, due March 7, 2029 (5.84% Notes) in reliance on an exemption from registration under Section 4(a)(2) of the Securities Act of 1933, as amended. The 5.78% Notes and the 5.84% Notes are expected to be issued on or about March 7, 2024, pursuant to the Note Purchase Agreement. The proceeds from the Note Purchase Agreement are expected to be used to refinance $150.0 million of existing term loans at NW Holdings and NWN Water. The 5.78% Notes will bear interest at the rate of 5.78% per annum, payable semi-annually on March 7 and September 7 of each year, commencing September 9, 2024, and will mature on March 7, 2028. NW Holdings may, at its option, prepay at any time all, or from time to time any part of, the outstanding 5.78% Notes at a price equal to 100% of the principal amount thereof, plus a “make-whole” premium and accrued and unpaid interest thereon to the date of prepayment; provided, however, in the case of a partial prepayment, NW Holdings must prepay at least 5% of the aggregate principal amount of the 5.78% Notes outstanding. At any time on or after February 7, 2028, NW Holdings may, at its option, prepay all or any part of the 5.78% Notes at 100% of the principal amount thereof, plus accrued and unpaid interest thereon to the date of prepayment, but without the payment of a “make-whole” premium, so long as there is no Default or Event of Default under the Note Purchase Agreement. The 5.84% Bonds will bear interest at the rate of 5.84% per annum, payable semi-annually on March 7 and September 7 of each year, commencing September 9, 2024, and will mature on March 7, 2029. NW Holdings may, at its option, prepay at any time all, or from time to time any part of, the outstanding 5.84% Notes at a price equal to 100% of the principal amount thereof, plus a “make-whole” premium and accrued and unpaid interest thereon to the date of prepayment; provided, however, in the case of a partial prepayment, NW Holdings must prepay at least 5% of the aggregate principal amount of the 5.84% Notes outstanding. At any time on or after February 7, 2029, NW Holdings may, at its option, prepay all or any part of the 5.84% Notes at 100% of the principal amount thereof, plus accrued and unpaid interest thereon to the date of prepayment, but without the payment of a “make-whole” premium, so long as there is no Default or Event of Default under the Note Purchase Agreement. Interest Rate Swap Agreements NW Holdings and NWN Water entered into interest rate swap agreements with major financial institutions that effectively convert variable-rate debt to a fixed rate. Interest payments made between the effective date and expiration date are hedged by the swap agreements. The notional amount, effective date, expiration date and benchmark rate of the swap agreements are shown in the table below: In millions Notional Amount Effective Date Expiration Date Fixed Rate NW Holdings $ 100.0 1/17/2023 3/15/2024 4.7 % NWN Water $ 55.0 1/19/2023 6/10/2026 3.8 % Maturities and Outstanding Long-Term Debt Retirement of long-term debt for each of the annual periods through December 31, 2028 and thereafter are as follows: In thousands NW Natural Other (NW Holdings) NW Holdings 2024 $ — $ 150,868 $ 150,868 2025 30,000 824 30,824 2026 55,000 55,852 110,852 2027 64,700 881 65,581 2028 10,000 866 10,866 Thereafter 1,215,000 2,353 1,217,353 Total $ 1,374,700 $ 211,644 $ 1,586,344 The following table presents debt outstanding at NW Natural as of December 31: In thousands 2023 2022 NW Natural: First Mortgage Bonds: 3.542% Series due 2023 $ — $ 50,000 5.620% Series due 2023 — 40,000 7.720% Series due 2025 20,000 20,000 6.520% Series due 2025 10,000 10,000 7.050% Series due 2026 20,000 20,000 3.211% Series due 2026 35,000 35,000 7.000% Series due 2027 20,000 20,000 2.822% Series due 2027 25,000 25,000 6.650% Series due 2027 19,700 19,700 6.650% Series due 2028 10,000 10,000 3.141% Series due 2029 50,000 50,000 7.740% Series due 2030 20,000 20,000 7.850% Series due 2030 10,000 10,000 5.820% Series due 2032 30,000 30,000 5.660% Series due 2033 40,000 40,000 5.750% Series due 2033 100,000 — 5.180% Series due 2034 80,000 — 5.250% Series due 2035 10,000 10,000 5.230% Series due 2038 50,000 — 4.000% Series due 2042 50,000 50,000 4.136% Series due 2046 40,000 40,000 3.685% Series due 2047 75,000 75,000 4.110% Series due 2048 50,000 50,000 3.869% Series due 2049 90,000 90,000 3.600% Series due 2050 150,000 150,000 3.078% Series due 2051 130,000 130,000 4.780% Series due 2052 140,000 140,000 5.430% Series due 2053 100,000 — Long-term debt, gross 1,374,700 1,134,700 Less: current maturities — 90,000 Total long-term debt $ 1,374,700 $ 1,044,700 Fair Value of Long-Term Debt NW Holdings' and NW Natural's outstanding debt does not trade in active markets. The fair value of debt is estimated using the value of outstanding debt at natural gas distribution companies with similar credit ratings, terms, and remaining maturities to NW Holdings' and NW Natural's debt that actively trade in public markets. Substantially all outstanding debt at NW Holdings is comprised of NW Natural debt. These valuations are based on Level 2 inputs as defined in the fair value hierarchy. See Note 2. The following table provides an estimate of the fair value of long-term debt, including current maturities of long-term debt, using market prices in effect on the valuation date : December 31, In thousands 2023 2022 NW Natural: Gross long-term debt $ 1,374,700 $ 1,134,700 Unamortized debt issuance costs (9,968) (8,823) Carrying amount 1,364,732 1,125,877 Estimated fair value (1) 1,236,559 944,383 NW Holdings: Gross long-term debt $ 1,586,344 $ 1,345,851 Unamortized debt issuance costs (10,044) (8,987) Carrying amount 1,576,300 1,336,864 Estimated fair value (1) 1,447,941 1,148,395 (1) Estimated fair value does not include unamortized debt issuance costs. |
Income Tax
Income Tax | 12 Months Ended |
Dec. 31, 2023 | |
Income Tax Disclosure [Abstract] | |
Income Tax [Text Block] | INCOME TAX The following table provides a reconciliation between income taxes calculated at the statutory federal tax rate and the provision for income taxes reflected in the NW Holdings and NW Natural statements of comprehensive income or loss for December 31: NW Holdings NW Natural Dollars in thousands 2023 2022 2021 2023 2022 2021 Income taxes at federal statutory rate $ 26,508 $ 24,241 $ 22,275 $ 29,486 $ 25,746 $ 22,996 Increase (decrease): State income tax, net of federal 10,875 10,139 9,962 11,510 10,504 10,150 Differences required to be flowed-through by regulatory commissions (3,976) (4,748) (4,655) (3,972) (4,746) (4,738) Other, net (1,045) (502) (176) (1,352) (468) (75) Total provision for income taxes $ 32,362 $ 29,130 $ 27,406 $ 35,672 $ 31,036 $ 28,333 Effective tax rate 25.6% 25.2% 25.8% 25.4% 25.3% 25.9% The NW Holdings and NW Natural effective income tax rates for 2023 compared to 2022 changed primarily as a result of pre-tax income. The NW Holdings and NW Natural effective income tax rates for 2022 compared to 2021 changed primarily due to lower income tax amortization in 2022 of the 2020 Oregon Corporate Activity Tax (CAT), which was subject to regulatory deferral when it became effective on January 1, 2020 and then amortized in income tax expense as recovery began in late 2020, 2021, and 2022. The provision for current and deferred income taxes consists of the following at December 31: NW Holdings NW Natural In thousands 2023 2022 2021 2023 2022 2021 Current Federal $ 13,496 $ 5,172 $ 6,508 $ 20,512 $ 7,442 $ 7,570 State 9,901 6,551 6,281 12,304 7,307 7,540 Total current income taxes 23,397 11,723 12,789 32,816 14,749 15,110 Deferred Federal 5,100 11,124 8,289 591 10,298 7,915 State 3,865 6,283 6,328 2,265 5,989 5,308 Total deferred income taxes 8,965 17,407 14,617 2,856 16,287 13,223 Income tax provision $ 32,362 $ 29,130 $ 27,406 $ 35,672 $ 31,036 $ 28,333 The following table summarizes the tax effect of significant items comprising NW Holdings and NW Natural's deferred income tax balances recorded at December 31: NW Holdings NW Natural In thousands 2023 2022 2023 2022 Deferred tax liabilities: Plant and property $ 350,802 $ 326,326 $ 340,042 $ 320,121 Leases receivable 35,635 36,873 35,635 36,873 Pension and postretirement obligations 24,830 22,973 24,830 22,973 Income tax regulatory asset 12,939 13,152 12,939 13,152 Lease right of use assets 21,002 21,272 20,849 21,084 Other Intangibles 528 — — — Other 4,432 17,050 4,620 17,314 Total deferred income tax liabilities 450,168 437,646 438,915 431,517 Deferred income tax assets: Income tax regulatory liability 46,372 48,270 46,120 48,018 Lease liabilities 21,047 21,306 20,884 21,102 Other intangible assets — 1,947 — — Net operating losses and credits carried forward 76 101 44 44 Total deferred income tax assets 67,495 71,624 67,048 69,164 Total net deferred income tax liabilities $ 382,673 $ 366,022 $ 371,867 $ 362,353 At December 31, 2023 and 2022, regulatory income tax assets of $8.0 million and $10.2 million, respectively, were recorded by NW Natural, a portion of which is recorded in current assets. These regulatory income tax assets primarily represent future rate recovery of deferred tax liabilities, resulting from differences in NGD plant financial statement and tax bases and NGD plant removal costs, which were previously flowed through for rate making purposes and to take into account the additional future taxes, which will be generated by that recovery. These deferred tax liabilities, and the associated regulatory income tax assets, are currently being recovered through customer rates. At December 31, 2023 and 2022, regulatory income tax assets of $4.9 million and $2.9 million, respectively, were recorded by NW Natural, representing future recovery of deferred tax liabilities resulting from the equity portion of AFUDC. At December 31, 2023 and 2022, deferred tax assets of $46.1 million and $48.0 million, respectively, were recorded by NW Natural representing the future income tax benefit associated with the excess deferred income tax regulatory liability recorded as a result of the lower federal corporate income tax rate provided for by the TCJA. At December 31, 2023 and 2022, regulatory liability balances representing the benefit of the change in deferred taxes as a result of the TCJA of $174.2 million and $181.4 million, respectively, were recorded by NW Natural. NW Holdings and NW Natural assess the available positive and negative evidence to estimate if sufficient taxable income will be generated to utilize their respective existing deferred tax assets. Based upon this assessment, NW Holdings and NW Natural determined that it is more likely than not that all of their respective deferred tax assets recorded as of December 31, 2023 will be realized. The Company estimates it has net operating loss (NOL) carryforwards of $29 thousand for federal taxes and $29 thousand for state taxes at December 31, 2023. The federal NOLs do not expire and we anticipate fully utilizing the state NOL carryforward balances before they begin to expire in 2040. California alternative minimum tax (AMT) credits of $56 thousand are also available. The AMT credits do not expire. Uncertain tax positions are accounted for in accordance with accounting standards that require an assessment of the anticipated settlement outcome of material uncertain tax positions taken in a prior year, or planned to be taken in the current year. Until such positions are sustained, the uncertain tax benefits resulting from such positions would not be recognized. No reserves for uncertain tax positions were recorded as of December 31, 2023, 2022, or 2021. The federal income tax returns for tax years 2019 and earlier are closed by statute. The IRS Compliance Assurance Process (CAP) examination of the 2020 and 2021 tax years have been completed. There were no material changes to these returns as filed. The 2022 and 2023 tax years are currently under IRS CAP examination. The 2024 CAP application has been filed. Under the CAP program, NW Holdings and NW Natural work with the IRS to identify and resolve material tax matters before the tax return is filed each year. |
Property, Plant and Equipment
Property, Plant and Equipment | 12 Months Ended |
Dec. 31, 2023 | |
Public Utilities, Property, Plant and Equipment [Abstract] | |
Property, Plant and Equipment [Text Block] | PROPERTY, PLANT, AND EQUIPMENT The following table sets forth the major classifications of property, plant, and equipment and accumulated depreciation of continuing operations at December 31: In thousands 2023 2022 NW Natural: NGD plant in service $ 4,206,455 $ 3,992,676 NGD construction work in progress 105,166 78,897 Less: Accumulated depreciation 1,159,367 1,115,690 NGD plant, net 3,152,254 2,955,883 Other plant in service 71,175 70,368 Other construction work in progress 10,963 6,606 Less: Accumulated depreciation 22,595 21,541 Other plant, net 59,543 55,433 Total property, plant, and equipment $ 3,211,797 $ 3,011,316 Other (NW Holdings): Other plant in service $ 147,040 $ 92,979 Other construction work in progress 15,810 20,040 Less: Accumulated depreciation 16,593 9,935 Other plant, net 146,257 103,084 NW Holdings: Total property, plant, and equipment $ 3,358,054 $ 3,114,400 NW Natural: Capital expenditures in accrued liabilities $ 24,168 $ 24,584 NW Holdings: Capital expenditures in accrued liabilities $ 27,879 $ 25,318 Accumulated depreciation does not include the accumulated provision for asset removal costs of $496.2 million and $467.7 million at December 31, 2023 and 2022, respectively. These accrued asset removal costs are reflected on the balance sheet as regulatory liabilities. See Note 2. NW Holdings Other plant balances include long-lived assets associated with water and wastewater operations and non-regulated activities not held by NW Natural or its subsidiaries. NW Natural Other plant balances include non-utility gas storage assets at the Mist facility and other long-lived assets not related to NGD. The weighted average depreciation rate for NGD assets was 3.0% in 2023, 2022, and 2021. The weighted average depreciation rate for assets not related to NGD was 1.7% in 2023 and 1.8% in 2022 and 2021. |
Business Combinations Business
Business Combinations Business Combinations | 12 Months Ended |
Dec. 31, 2023 | |
Business Combinations [Abstract] | |
Business Combinations | BUSINESS COMBINATIONS 2023 Business Combinations During the year ended December 31, 2023, NWN Water and its subsidiaries acquired the assets of five businesses qualifying as business combinations. The aggregate fair value of the preliminary total consideration transferred for these acquisitions was $22.8 million, most of which was preliminarily allocated to property, plant, and equipment, and goodwill. These transactions align with NW Holdings' water and wastewater sector strategy as it continues to expand its water and wastewater service territories and included: • Pedersen Family, LLC in Washington • King Water Corporation in Washington • Rose Valley Water Company in Arizona • Hiland Water in Oregon • Truxton and Cerbat in Arizona Intangible Assets In connection with the acquisition of King Water Corporation, NWN Water recorded long-term customer relationship intangible assets totaling $2.6 million, which will be amortized over 24 years. There was no amortization expense recognized in 2023. Projected amortization expense at NW Holdings for customer relationship intangible assets for each of the next five years is $0.1 million in each period. The amortization will change in future periods if other intangible assets are acquired, impairments are recognized or the preliminary valuations as part of our purchase price allocation is refined. 2022 Business Combinations Far West Water & Sewer, Inc. On October 5, 2022, NWN Water completed the acquisition of the water and wastewater utilities of Far West Water & Sewer, Inc. (Far West), which has a combined approximately 25,000 connections in Yuma, Arizona. The acquisition-date fair value of the total consideration transferred, after closing adjustments, was approximately $97.0 million, of which $88.4 million was cash consideration transferred at closing, $8.1 million was contingent consideration, and $0.5 million was deferred consideration. The contingent consideration is an earnout payment in an amount equal to the product of (i) the amount, if any, by which the average annual System Operating Revenue for the 2026, 2027, and 2028 years exceeds $13.0 million (ii) multiplied by 4 but shall not exceed $12.0 million. As of the acquisition date, the contingent consideration had a fair value of $8.1 million and was included in other non-current liabilities. The fair value as of the acquisition date was determined using a scenario-based technique using management's best estimate of forecast revenue for the years 2026, 2027, and 2028 discounted to present value. The inputs to determine the fair value of the contingent consideration include estimated future revenue and a risk-adjusted discount rate. The fair value measurement is based on significant inputs that are not observable in the market and thus represents a fair value measurement categorized within Level 3 of the fair value hierarchy per ASC Topic 820. The Far West acquisition met the criteria of a business combination, and as such an allocation of the consideration to the acquired net assets based on their estimated fair value as of the acquisition date was performed. In accordance with U.S. GAAP, the fair value determination involves management judgment in determining the significant estimates and assumptions used and was made using existing regulatory conditions for net assets associated with Far West. The acquisition costs were expensed as incurred. Goodwill of $69.9 million was recognized from this acquisition. The goodwill recognized is attributable to Far West's regulated water utility service territory, experienced workforce, and the strategic benefits for both the water utility and wastewater services expected from growth in its service territory. No intangible assets aside from goodwill were recognized. The amount of goodwill that is expected to be deductible for income tax purposes is approximately $63.3 million. The purchase price for the acquisition has been allocated to the net assets acquired as of the acquisition date and is as follows: In thousands December 31, 2023 Current assets $ 1,569 Property, plant and equipment 25,974 Goodwill 69,890 Non-current assets 1,077 Current liabilities (991) Non-current liabilities (9,115) Total net assets acquired $ 88,404 The amount of Far West revenues included in NW Holdings' consolidated statements of comprehensive income is $2.9 million for the year ended December 31, 2022. Earnings from Far West activities for the year ended December 31, 2022 were not material to the results of NW Holdings. Far West is referred to as Foothills Utilities following the closure of the acquisition. Other 2022 Business Combinations During the year ended December 31, 2022, NWN Water and its subsidiaries acquired the assets of six additional businesses qualifying as business combinations. The aggregate fair value of the consideration transferred for these acquisitions was $8.7 million, most of which was allocated to property, plant and equipment and goodwill. These transactions align with NW Holdings' water and wastewater sector strategy as it continues to expand its water and wastewater service territories and included: • Belle Oaks Water and Sewer Co., Inc in Texas • Northwest Water Services, LLC in Washington • Aquarius Utilities, LLC in Washington • Valiant Idaho, LLC (The Idaho Club - Sewer) in Idaho • Caney Creek in Texas • Water Necessities, Inc. and Rural Water Co. in Texas 2021 Business Combinations During the year ended December 31, 2021, NWN Water and its subsidiaries completed four acquisitions qualifying as business combinations. The aggregate fair value of the consideration transferred for these acquisitions were not material and are not significant to NW Holdings' results of operations. Goodwill NW Holdings allocates goodwill to reporting units based on the expected benefit from the business combination. We perform an annual impairment assessment of goodwill at the reporting unit level, or more frequently if events and circumstances indicate that goodwill might be impaired. An impairment loss is recognized if the carrying value of a reporting unit’s goodwill exceeds its fair value. As a result of all acquisitions completed, total goodwill was $163.3 million as of December 31, 2023 and $149.3 million as of December 31, 2022. The increase in the goodwill balance was primarily due to additions associated with our acquisitions in the water and wastewater sector. All of our goodwill is related to water and wastewater acquisitions and is included in the other category for segment reporting purposes. The annual impairment assessment of goodwill occurs in the fourth quarter of each year. There have been no impairments recognized to date. |
Derivative Instruments
Derivative Instruments | 12 Months Ended |
Dec. 31, 2023 | |
Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
Derivative Instruments | DERIVATIVE INSTRUMENTS NW Natural NW Natural enters into financial derivative contracts to hedge a portion of the NGD segment’s natural gas sales requirements. These contracts include swaps, options, and option combinations. These derivative financial instruments are primarily used to manage commodity price variability. A small portion of NW Natural's derivative hedging strategy involves foreign currency forward contracts. NW Natural enters into these financial derivatives, up to prescribed limits, primarily to hedge price variability related to term physical gas supply contracts. The foreign currency forward contracts are used to hedge the fluctuation in foreign currency exchange rates for pipeline demand charges paid in Canadian dollars. In the normal course of business, NW Natural also enters into indexed-price physical forward natural gas commodity purchase contracts and options to meet the requirements of NGD customers. These contracts qualify for regulatory deferral accounting treatment. Notional Amounts The following table presents the absolute notional amounts related to open positions on NW Natural derivative instruments: At December 31, In thousands 2023 2022 Natural gas (in therms): Financial 948,425 852,435 Physical 571,610 463,254 Foreign exchange $ 11,926 $ 7,617 Purchased Gas Adjustment (PGA) Rates and hedging approaches may vary between states due to different rate structures and mechanisms. Under the PGA mechanism in Oregon, derivatives entered into by NW Natural for the procurement or hedging of natural gas for future gas years generally receive regulatory deferral accounting treatment. In general, commodity hedging for the current gas year is completed prior to the start of the gas year, and hedge prices are reflected in the weighted-average cost of gas in the PGA filing. Hedge contracts entered into after the start of the PGA period are subject to the PGA incentive sharing mechanism in Oregon. Under the PGA mechanism in Washington, NW Natural incorporates a risk-responsive hedging strategy, and receives regulatory deferral accounting treatment for its Washington gas supplies. NW Natural entered the 2022-23 gas year with total forecasted sales volumes hedged at approximately 84%, including 67% in financial hedges and 17% in physical gas supplies. The total hedged was approximately 85% in Oregon and 79% in Washington. NW Natural entered the 2023-24 gas year with total forecasted sales volume hedged at approxima tely 82%, including 66% in financial hedges and 16% in physical gas supplies. The total hedged was approximately 85% in Oregon and 55% in Washington. Unrealized and Realized Gain/Loss The following table reflects the income statement presentation for the unrealized gains and losses from NW Natural's derivative instruments: December 31, 2023 December 31, 2022 In thousands Natural gas commodity Foreign exchange Natural gas commodity Foreign exchange Benefit (expense) to cost of gas $ (131,833) $ 168 $ 119,935 $ (165) Operating revenues (expense) — — — — Amounts deferred to regulatory accounts on balance sheet 131,833 (168) (119,935) 165 Total gain (loss) in pre-tax earnings $ — $ — $ — $ — Unrealized Gain/Loss Outstanding derivative instruments related to regulated NGD operations are deferred in accordance with regulatory accounting standards. The cost of foreign currency forward and natural gas derivative contracts are recognized immediately in the cost of gas; however, costs above or below the amount embedded in the current year PGA are subject to a regulatory deferral tariff and therefore, are recorded as a regulatory asset or liability. Realized Gain/Loss NW Natural realized a net gain of $ 125.5 million 107.8 million Credit Risk Management of Financial Derivatives Instruments No collateral was posted with or by NW Natural counterparties as of December 31, 2023 or 2022. NW Natural attempts to minimize the potential exposure to collateral calls by diversifying counterparties and using credit limits to manage liquidity risk. Counterparties generally allow a certain credit limit threshold before requiring NW Natural to post collateral against unrealized loss positions. Given NW Natural's credit ratings, counterparty credit limits and portfolio diversification, it was not subject to collateral calls in 2023 or 2022. The collateral call exposure is set forth under credit support agreements, which generally contain credit limits. NW Natural could also be subject to collateral call exposure where it has agreed to provide adequate assurance, which is not specific as to the amount of credit limit allowed, but could potentially require additional collateral posting by NW Natural in the event of a material adverse change. NW Natural's financial derivative instruments are subject to master netting arrangements; however, they are presented on a gross basis in the consolidated balance sheets. NW Natural and its counterparties have the ability to set-off obligations to each other under specified circumstances. Such circumstances may include a defaulting party, a credit change due to a merger affecting either party, or any other termination event. If netted by counterparty, NW Natural's physical and financial derivative position would result in an asset of $9.0 million and a liability of $124.2 million as of December 31, 2023, and an asset of $153.3 million and a liability of $3.6 million as of December 31, 2022. NW Natural is exposed to derivative credit and liquidity risk primarily through securing fixed-price natural gas commodity swaps and interest rate swaps with financial counterparties. NW Natural utilizes master netting arrangements with International Swaps and Derivatives Association (ISDA) contracts to minimize these risks including ISDA Credit Support Agreements with counterparties based on their credit ratings. Additionally, NW Natural uses counterparty, industry, sector and country diversification to minimize credit risk. In certain cases, NW Natural may require counterparties to post collateral, guarantees, or letters of credit to maintain its minimum credit requirement standards or for liquidity management purposes. NW Natural's financial derivatives policy requires counterparties to have an investment-grade credit rating at the time the derivative instrument is entered into, and specifies limits on the contract amount and duration based on each counterparty’s credit rating. NW Natural does not speculate in derivatives. Derivatives are used to manage NW Natural's market risk and we hedge exposure above risk tolerance limits. It is required that increases in market risk created by the use of derivatives is offset by the exposures they modify. We actively monitor NW Natural's derivative credit exposure and place counterparties on hold for trading purposes or require other forms of credit assurance, such as letters of credit, cash collateral, or guarantees as circumstances warrant. The ongoing assessment of counterparty credit risk includes consideration of credit ratings, credit default swap spreads, bond market credit spreads, financial conditions, government actions, and market news. A Monte Carlo simulation model is used to estimate the change in credit and liquidity risk from the volatility of natural gas prices. The results of the model are used to establish trading limits. NW Natural's outstanding financial derivatives at December 31, 2023 mature by November 1, 2026. We could become materially exposed to credit risk with one or more of our counterparties if natural gas prices experience a significant increase. If a counterparty were to become insolvent or fail to perform on its obligations, we could suffer a material loss; however, we would expect such a loss to be eligible for regulatory deferral and rate recovery, subject to a prudence review. All of our existing counterparties currently have investment-grade credit ratings. Fair Value In accordance with fair value accounting, NW Natural includes non-performance risk in calculating fair value adjustments. This includes a credit risk adjustment based on the credit spreads of NW Natural counterparties when in an unrealized gain position, or on NW Natural's own credit spread when it is in an unrealized loss position. The inputs in our valuation models include natural gas futures, volatility, credit default swap spreads, and interest rates. Additionally, the assessment of non-performance risk is generally derived from the credit default swap market and from bond market credit spreads. The impact of the credit risk adjustments for all financial derivatives outstanding to the fair value calculation was $0.7 million at December 31, 2023. As of December 31, 2023 and 2022, the net fair value was a liability of $115.2 million and an asset of $149.7 million, respectively, using significant other observable, or Level 2, inputs. No Level 3 inputs were used in our derivative valuations during the years ended December 31, 2023 and 2022. NW Holdings NW Holdings and NWN Water entered into interest rate swap agreements with major financial institutions that effectively converted variable-rate debt to a fixed rate. Interest payments made between the effective date and expiration date are hedged by the swap agreements. The notional amount, effective date, expiration date and benchmark rate of the swap agreements are shown in the table below: In millions Notional Amount Effective Date Expiration Date Fixed Rate NW Holdings $ 100.0 1/17/2023 3/15/2024 4.7 % NWN Water $ 55.0 1/19/2023 6/10/2026 3.8 % Unrealized gains and losses related to these interest rate swap agreements are recorded in AOCI on the consolidated balance sheet and totaled $0.2 million and $0.1 million, net of tax, as of December 31, 2023 and 2022, respectively. There were no amounts reclassified from AOCI to net income during the year ended December 31, 2023 and 2022. |
Commitments and Contigencies
Commitments and Contigencies | 12 Months Ended |
Dec. 31, 2023 | |
Commitments and Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | COMMITMENTS AND CONTINGENCIES Gas Purchase Agreements NW Natural enters into short-term and long-term physical baseload gas purchase agreements. The majority of our gas purchase agreements include year-round, winter-only, summer-only, and monthly purchases. Pipeline Capacity Purchase and Release Commitments NW Natural has signed agreements providing for the reservation of firm pipeline capacity under which it is required to make monthly payments for contracted capacity. The pricing component of the monthly payment is established, subject to change, by U.S. or Canadian regulatory bodies, or is established directly with private counterparties, as applicable. In addition, NW Natural has entered into long-term agreements to release firm pipeline capacity. The parties that we release this capacity to make payments directly to the related pipelines. The aggregate amounts of these agreements at NW Natural were as follows at December 31, 2023: In thousands Gas Purchase Agreements (1) Pipeline Pipeline 2024 $ 303,682 $ 78,907 $ 7,543 2025 34,457 81,114 3,455 2026 34,586 66,972 — 2027 33,830 67,123 — 2028 33,980 63,812 — Thereafter 208,426 377,175 — Total 648,961 735,103 10,998 Less: Amount representing interest 96,491 183,620 373 Total at present value $ 552,470 $ 551,483 $ 10,625 (1) Gas purchase agreements include environmental attributes of RNG. Total fixed charges under capacity purchase agreements were $87.0 million for 2023, $90.2 million for 2022, and $82.9 million for 2021, of which $8.2 million, $8.3 million, and $7.7 million, respectively, related to capacity releases which third parties paid directly to the related pipelines. In addition, per-unit charges are required to be paid based on the actual quantities shipped under the agreements. In certain take-or-pay purchase commitments, annual deficiencies may be offset by prepayments subject to recovery over a longer term if future purchases exceed the minimum annual requirements. Leases Refer to Note 7 for a discussion of lease commitments and contingencies. Environmental Matters Refer to Note 17 for a discussion of environmental commitments and contingencies. |
Environmental Matters
Environmental Matters | 12 Months Ended |
Dec. 31, 2023 | |
Environmental Remediation Obligations [Abstract] | |
Environmental Matters | ENVIRONMENTAL MATTERS NW Natural owns, or previously owned, properties that may require environmental remediation or action. The range of loss for environmental liabilities is estimated based on current remediation technology, enacted laws and regulations, industry experience gained at similar sites, and an assessment of the probable level of involvement and financial condition of other potentially responsible parties (PRPs). When amounts are prudently expended related to site remediation of those sites described herein, NW Natural has recovery mechanisms in place to collect 96.7% of remediation costs allocable to Oregon customers and 3.3% of costs allocable to Washington customers. These sites are subject to the remediation process prescribed by the Environmental Protection Agency (EPA) and the Oregon Department of Environmental Quality (ODEQ). The process begins with a remedial investigation (RI) to determine the nature and extent of contamination and then a risk assessment (RA) to establish whether the contamination at the site poses unacceptable risks to humans and the environment. Next, a feasibility study (FS) or an engineering evaluation/cost analysis (EE/CA) evaluates various remedial alternatives. It is at this point in the process when NW Natural is able to estimate a range of remediation costs and record a reasonable potential remediation liability, or make an adjustment to the existing liability. From this study, the regulatory agency selects a remedy and issues a Record of Decision (ROD). After a ROD is issued, NW Natural would seek to negotiate a consent decree or consent judgment for designing and implementing the remedy. NW Natural would have the ability to further refine estimates of remediation liabilities based upon an approved remedial design. Remediation may include treatment of contaminated media such as sediment, soil and groundwater, removal and disposal of media, institutional controls such as legal restrictions on future property use, or natural recovery. Following construction of the remedy, the EPA and ODEQ also have requirements for ongoing maintenance, monitoring and other post-remediation care that may continue for many years. Where appropriate and reasonably known, NW Natural will provide for these costs in the remediation liabilities described below. Due to the numerous uncertainties surrounding the course of environmental remediation and the preliminary nature of several site investigations, in some cases, NW Natural may not be able to reasonably estimate the high end of the range of possible loss. In those cases, the nature of the possible loss has been disclosed, as has the fact that the high end of the range cannot be reasonably estimated where a range of potential loss is available. Unless there is an estimate within the range of possible losses that is more likely than other cost estimates within that range, NW Natural records the liability at the low end of this range. It is likely changes in these estimates and ranges will occur throughout the remediation process for each of these sites due to the continued evaluation and clarification concerning responsibility, the complexity of environmental laws and regulations and the determination by regulators of remediation alternatives. In addition to remediation costs, NW Natural could also be subject to Natural Resource Damages (NRD) claims. NW Natural will assess the likelihood and probability of each claim and recognize a liability if deemed appropriate. Refer to " Other Portland Harbor " below. Environmental Sites The following table summarizes information regarding liabilities related to environmental sites, which are recorded in other current liabilities and other noncurrent liabilities in NW Natural's balance sheet at December 31: Current Liabilities Non-Current Liabilities In thousands 2023 2022 2023 2022 Portland Harbor site: Gasco/Siltronic Sediments $ 12,428 $ 9,744 $ 42,550 $ 42,120 Other Portland Harbor 3,035 2,634 11,270 11,270 Gasco/Siltronic Upland site 16,304 16,067 34,235 35,457 Front Street site 687 457 939 879 Oregon Steel Mills — — 179 179 Total $ 32,454 $ 28,902 $ 89,173 $ 89,905 Portland Harbor Site The Portland Harbor is an EPA listed Superfund site that is approximately 10 miles long on the Willamette River and is adjacent to NW Natural's Gasco uplands site. NW Natural is one of over one hundred PRPs, each jointly and severally liable, at the Superfund site. In January 2017, the EPA issued its Record of Decision, which selects the remedy for the clean-up of the Portland Harbor site (Portland Harbor ROD). The Portland Harbor ROD estimates the present value total cost at approximately $1.05 billion with an accuracy between -30% and +50% of actual costs. NW Natural's potential liability is a portion of the costs of the remedy for the entire Portland Harbor Superfund site. The cost of that remedy is expected to be allocated among more than one hundred PRPs. NW Natural is participating in a non-binding allocation process with other PRPs in an effort to resolve its potential liability. The Portland Harbor ROD does not provide any additional clarification around allocation of costs among PRPs; accordingly, NW Natural has not modified any of the recorded liabilities at this time as a result of the issuance of the Portland Harbor ROD. NW Natural manages its liability related to the Superfund site as two distinct remediation projects, the Gasco Sediments Site and Other Portland Harbor projects. GASCO SEDIMENTS. In 2009, NW Natural and Siltronic Corporation entered into a separate Administrative Order on Consent with the EPA to evaluate and design specific remedies for sediments adjacent to the Gasco uplands and Siltronic uplands sites. NW Natural submitted a draft EE/CA to the EPA in May 2012 to provide the estimated cost of potential remedial alternatives for this site. In March 2020, NW Natural and the EPA amended the Administrative Order on Consent to include additional remedial design activities downstream of the Gasco sediments site and in the navigation channel. Siltronic Corporation is not a party to the amended order. NW Natural is completing pre-design studies and has submitted a draft Basis of Design Report. These preliminary design steps do not include a cost estimate for cleanup. No remedial design is more likely than the EE/CA alternatives at this time, and NW Natural expects further design discussion and iteration with the EPA. The estimated costs for the various sediment remedy alternatives in the draft EE/CA for the additional studies and design work needed before the cleanup can occur, and for regulatory oversight throughout the cleanup range from $55.0 million to $350 million. NW Natural has recorded a liability of $55.0 million for the Gasco sediment clean-up, which reflects the low end of the range. At this time, we believe sediments at the Gasco sediments site represent the largest portion of NW Natural's liability related to the Portland Harbor site discussed above. In September 2023, the EPA approved the In Situ Stabilization and Solidification (ISS) Work Plan for the ISS field pilot study, which was successfully completed during the fall of 2023. Information obtained from the pilot study will be used to support remedial design of the Gasco sediments project. OTHER PORTLAND HARBOR. While we believe liabilities associated with the Gasco sediments site represent NW Natural's largest exposure, there are other potential exposures associated with the Portland Harbor ROD, including NRD costs and harborwide remedial design and cleanup costs (including downstream petroleum contamination), for which allocations among the PRPs have not yet been determined. NW Natural and other parties have signed a cooperative agreement with the Portland Harbor Natural Resource Trustee council to participate in a phased NRD assessment to estimate liabilities to support an early restoration-based settlement of NRD claims. One member of this Trustee council, the Yakama Nation, withdrew from the council in 2009, and in 2017, filed suit against NW Natural and 29 other parties seeking remedial costs and NRD assessment costs associated with the Portland Harbor site, set forth in the complaint. The complaint seeks recovery of alleged costs totaling $0.3 million in connection with the selection of a remedial action for the Portland Harbor site as well as declaratory judgment for unspecified future remedial action costs and for costs to assess the injury, loss or destruction of natural resources resulting from the release of hazardous substances at and from the Portland Harbor site. The Yakama Nation has filed two amended complaints addressing certain pleading defects and dismissing the State of Oregon. On the motion of NW Natural and certain other defendants the federal court has stayed the case pending the outcome of the non-binding allocation proceeding discussed above. NW Natural has recorded a liability for NRD claims which is at the low end of the range of the potential liability; the high end of the range cannot be reasonably estimated at this time. The NRD liability is not included in the aforementioned range of costs provided in the Portland Harbor ROD. Gasco Uplands Site A predecessor of NW Natural, Portland Gas and Coke Company, owned a former gas manufacturing plant that was closed in 1958 (Gasco site) and is adjacent to the Portland Harbor site described above. The Gasco site has been under investigation by NW Natural for environmental contamination under the ODEQ Voluntary Cleanup Program (VCP). It is not included in the range of remedial costs for the Portland Harbor site noted above. The Gasco site is managed in two parts, the uplands portion and the groundwater source control action. NW Natural submitted a revised Remedial Investigation Report for the uplands to ODEQ in May 2007. In March 2015, ODEQ approved the Risk Assessment (RA) for this site, enabling commencement of work on the FS in 2016. A draft FS is currently anticipated to be submitted in 2024. NW Natural has recognized a liability for the remediation of the uplands portion of the site which is at the low end of the range of potential liability; the high end of the range cannot be reasonably estimated at this time. In October 2016, ODEQ and NW Natural agreed to amend their VCP agreement for the Gasco uplands to incorporate a portion of the Siltronic property formerly owned by Portland Gas & Coke between 1939 and 1960 into the Gasco RA and FS. Previously, NW Natural was conducting an investigation of manufactured gas plant constituents on the entire Siltronic uplands for ODEQ. Siltronic will be working with ODEQ directly on environmental impacts to the remainder of its property. In September 2013, NW Natural completed construction of a groundwater source control system, including a water treatment station, at the Gasco site. NW Natural has estimated the cost associated with the ongoing operation of the system and has recognized a liability which is at the low end of the range of potential cost. NW Natural cannot estimate the high end of the range at this time due to the uncertainty associated with the duration of running the water treatment station, which is highly dependent on the remedy determined for both the upland portion as well as the final remedy for the Gasco sediments site. Other Sites In addition to those sites above, NW Natural has environmental exposures at three other sites: Central Service Center, Front Street and Oregon Steel Mills. NW Natural may have exposure at other sites that have not been identified at this time. Due to the uncertainty of the design of remediation, regulation, timing of the remediation and in the case of the Oregon Steel Mills site, pending litigation, liabilities for each of these sites have been recognized at their respective low end of the range of potential liability; the high end of the range could not be reasonably estimated at this time. FRONT STREET SITE. The Front Street site was the former location of a gas manufacturing plant NW Natural operated (the former Portland Gas Manufacturing site, or PGM). At ODEQ’s request, NW Natural conducted a sediment and source control investigation and provided findings to ODEQ. In December 2015, an FS on the former Portland Gas Manufacturing site was completed. In July 2017, ODEQ issued the PGM ROD. The ROD specifies the selected remedy, which requires a combination of dredging, capping, treatment, and natural recovery. In addition, the selected remedy also requires institutional controls and long-term inspection and maintenance. Construction of the remedy began in July 2020 and was completed in October 2020. The first year of post-construction monitoring was completed in 2021 and demonstrated that the cap was intact and performing as designed. NW Natural has recognized an additional liability of $1.6 million for costs associated with the discovery during construction of World War II-era munitions, design costs, regulatory and permitting issues, and post-construction work. OREGON STEEL MILLS SITE. Refer to “Legal Proceedings,” below. Environmental Cost Deferral and Recovery NW Natural has authorizations in Oregon and Washington to defer costs related to remediation of properties that are owned or were previously owned by NW Natural. In Oregon, a Site Remediation and Recovery Mechanism (SRRM) is currently in place to recover prudently incurred costs allocable to Oregon customers, subject to an earnings test. On October 21, 2019 the WUTC authorized an Environmental Cost Recovery Mechanism (ECRM) for recovery of prudently incurred costs allocable to Washington customers beginning November 1, 2019. The following table presents information regarding the total regulatory asset deferred as of December 31: In thousands 2023 2022 Deferred costs and interest (1) $ 57,758 $ 47,666 Accrued site liabilities (2) 121,575 118,763 Insurance proceeds and interest (50,764) (54,784) Total regulatory asset deferral (1) 128,569 111,645 Current regulatory assets (3) 9,950 7,392 Long-term regulatory assets (3) 118,619 104,253 (1) Includes pre-review and post-review deferred costs, amounts currently in amortization, and interest, net of amounts collected from customers. (2) Excludes 3.3% of the Front Street site liability as the OPUC only allows recovery of 96.7% of costs for those sites allocable to Oregon, including those that historically served only Oregon customers. Amounts excluded from regulatory assets were $53 thousand in 2023 and $43 thousand in 2022. (3) Environmental costs relate to specific sites approved for regulatory deferral by the OPUC and WUTC. In Oregon, NW Natural earns a carrying charge on cash amounts paid, whereas amounts accrued but not yet paid do not earn a carrying charge until expended. It also accrues a carrying charge on insurance proceeds for amounts owed to customers. In Washington, neither the cash paid nor insurance proceeds received accrue a carrying charge. Current environmental costs represent remediation costs management expects to collect from customers in the next 12 months. Amounts included in this estimate are still subject to a prudence and earnings test review by the OPUC and do not include the $5.0 million tariff rider. The amounts allocable to Oregon are recoverable through NGD rates, subject to an earnings test. See " Oregon SRRM " below. Oregon SRRM Collections From Oregon Customers Under the SRRM collection process, there are three types of deferred environmental remediation expense: • Pre-review - This class of costs represents remediation spend that has not yet been deemed prudent by the OPUC. Carrying costs on these remediation expenses are recorded at NW Natural's authorized cost of capital. NW Natural anticipates the prudence review for annual costs and approval of the earnings test prescribed by the OPUC to occur by the third quarter of the following year. • Post-review - This class of costs represents remediation spend that has been deemed prudent and allowed after applying the earnings test, but is not yet included in amortization. NW Natural earns a carrying cost on these amounts at a rate equal to the five-year treasury rate plus 100 basis points. • Amortization - This class of costs represents amounts included in current customer rates for collection and is generally calculated as one-fifth of the post-review deferred balance. NW Natural earns a carrying cost equal to the amortization rate determined annually by the OPUC, which approximates a short-term borrowing rate. In addition to the collection amount noted above, an order issued by the OPUC provides for the annual collection of $5.0 million from Oregon customers through a tariff rider. As NW Natural collects amounts from customers, it recognizes these collections as revenue and separately amortizes an equal and offsetting amount of its deferred regulatory asset balance through the environmental remediation operating expense line shown separately in the operating expense section of the income statement. NW Natural received total environmental insurance proceeds of approximately $150 million as a result of settlements from litigation that was dismissed in July 2014. Under a 2015 OPUC order which established the SRRM, one-third of the Oregon allocated proceeds were applied to costs deferred through 2012 with the remaining two-thirds applied to costs at a rate of $5.0 million per year plus interest over the following 20 years. NW Natural accrues interest on the Oregon allocated insurance proceeds in the customer’s favor at a rate equal to the five-year treasury rate plus 100 basis points. As of December 31, 2023, NW Natural has applied $100.7 million of insurance proceeds to prudently incurred remediation costs allocated to Oregon. Environmental Earnings Test To the extent NW Natural earns at or below its authorized Return on Equity (ROE) as defined by the SRRM, remediation expenses and interest in excess of the $5.0 million tariff rider and $5.0 million insurance proceeds are recoverable through the SRRM. To the extent NW Natural earns more than its authorized ROE in a year, it is required to cover environmental expenses and interest on expenses greater than the $10.0 million with those earnings that exceed its authorized ROE. Washington ECRM Washington Deferral On October 21, 2019, the WUTC issued an order (WUTC Order) establishing the ECRM which allows for recovery of past deferred and future prudently incurred environmental remediation costs allocable to Washington customers through application of insurance proceeds and collections from customers. Environmental remediation expenses relating to sites that previously served both Oregon and Washington customers are allocated between states with Washington customers receiving 3.3% percent of the costs and insurance proceeds. In accordance with the WUTC Order, insurance proceeds were fully applied to costs incurred between December 2018 and June 2019 that were deemed prudent. Remaining insurance proceeds will be amortized over a 10.5 year period ending December 31, 2029. As of December 31, 2023 , approximately $3.9 million of proceeds have been applied to prudently incurred costs. On an annual basis, NW Natural files for a prudence determination and a request to amortize costs to the extent that remediation expenses exceed the insurance amortization. After insurance proceeds are fully amortized, if in a particular year the request to collect deferred amounts exceeds one percent of Washington normalized revenues, then the excess will be collected over three years with interest. Legal Proceedings NW Holdings is not currently party to any direct claims or litigation, though in the future it may be subject to claims and litigation arising in the ordinary course of business. NW Natural is subject to claims and litigation arising in the ordinary course of business, including the matters discussed above. Although the final outcome of any of these legal proceedings cannot be predicted with certainty, including the matter relating to the Oregon Steel Mills site referenced below, NW Natural and NW Holdings do not expect that the ultimate disposition of any of these matters will have a material effect on their financial condition, results of operations, or cash flows. See also Part II, Item 1, “Legal Proceedings". Oregon Steel Mills Site In 2004, NW Natural was served with a third-party complaint by the Port of Portland (the Port) in a Multnomah County Circuit Court case, Oregon Steel Mills, Inc. v. The Port of Portland. The Port alleges that in the 1940s and 1950s petroleum wastes generated by NW Natural's predecessor, Portland Gas & Coke Company, and 10 other third-party defendants, were disposed of in a waste oil disposal facility operated by the United States or Shaver Transportation Company on property then owned by the Port and now owned by Evraz Oregon Steel Mills. The complaint seeks contribution for unspecified past remedial action costs incurred by the Port regarding the former waste oil disposal facility as well as a declaratory judgment allocating liability for future remedial action costs. No date has been set for trial. In August 2017, the case was stayed pending the outcome of the Portland Harbor allocation process or other mediation. Although the final outcome of this proceeding cannot be predicted with certainty, NW Natural and NW Holdings do not expect the ultimate disposition of this matter will have a material effect on NW Natural's or NW Holdings' financial condition, results of operations, or cash flows. |
Condensed Financials Standalone
Condensed Financials Standalone Holdco Condensed Financials Standalone Holdco (Notes) | 12 Months Ended |
Dec. 31, 2023 | |
Condensed Financial Statements, Captions [Line Items] | |
Condensed Financial Information of Parent Company Only Disclosure [Text Block] | SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF NORTHWEST NATURAL HOLDING COMPANY |
Valuation Allowances and Reserv
Valuation Allowances and Reserves | 12 Months Ended |
Dec. 31, 2023 | |
Entity Information [Line Items] | |
Schedule of Valuation and Qualifying Accounts | NORTHWEST NATURAL HOLDING COMPANY SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E Additions Deductions In thousands (year ended December 31) Balance at beginning of period Charged to costs and expenses Charged to other accounts Net write-offs Balance at end of period 2023 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 3,296 $ 2,869 $ 263 $ 2,973 $ 3,455 2022 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 2,018 $ 1,081 $ 1,810 $ 1,613 $ 3,296 2021 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 3,219 $ 724 $ (219) $ 1,706 $ 2,018 NORTHWEST NATURAL GAS COMPANY SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E Additions Deductions In thousands (year ended December 31) Balance at beginning of period Charged to costs and expenses Charged to other accounts Net write-offs Balance at end of period 2023 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 3,079 $ 2,859 $ 263 $ 2,973 $ 3,228 2022 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 1,962 $ 920 $ 1,810 $ 1,613 $ 3,079 2021 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 3,107 $ 780 $ (219) $ 1,706 $ 1,962 |
Significant Accounting Policies
Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2023 | |
Accounting Policies [Abstract] | |
Significant Accounting Policies | SIGNIFICANT ACCOUNTING POLICIES Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles in the United States of America (U.S. GAAP) requires management to make estimates and assumptions that affect reported amounts in the consolidated financial statements and accompanying notes. Actual amounts could differ from those estimates, and changes would most likely be reported in future periods. Management believes the estimates and assumptions used are reasonable . Industry Regulation NW Holdings' principal business is to operate as a holding company for NW Natural and its other subsidiaries. NW Natural's principal business is the distribution of natural gas, which is regulated by the OPUC and WUTC. NW Natural also has natural gas storage services, which are regulated by the FERC, and to a certain extent by the OPUC and WUTC. Additionally, certain of NW Holdings' subsidiaries own water businesses, which are regulated by the public utility commission in the state in which the water utility is located, which is currently Oregon, Washington, Idaho, Texas and Arizona. Wastewater businesses, to the extent they are regulated, are generally regulated by the public utility commissions in the state in which the wastewater utility is located, which is currently Texas and Arizona. Accounting records and practices of the regulated businesses conform to the requirements and uniform system of accounts prescribed by these regulatory authorities in accordance with U.S. GAAP. The businesses in which customer rates are regulated have approved cost-based rates which are intended to allow such businesses to earn a reasonable return on invested capital. In applying regulatory accounting principles, NW Holdings and NW Natural capitalize or defer certain costs and revenues as regulatory assets and liabilities pursuant to orders of the applicable state public utility commission, which provide for the recovery of revenues or expenses from, or refunds to, utility customers in future periods, including a return or a carrying charge in certain cases. Amounts NW Natural deferred as regulatory assets and liabilities were as follows: Regulatory Assets In thousands 2023 2022 NW Natural: Current: Unrealized loss on derivatives (1) $ 98,661 $ 28,728 Gas costs 9,301 61,223 Environmental costs (2) 9,950 7,392 Decoupling (3) 2,288 — Pension balancing (4) 7,131 7,131 Income taxes 2,208 2,208 Washington Climate Commitment Act compliance 20,537 — COVID-19 deferrals and expenses, net 9,685 789 Other (5) 18,509 10,020 Total current $ 178,270 $ 117,491 Non-current: Unrealized loss on derivatives (1) $ 28,055 $ 20,838 Pension balancing (4) 27,460 32,997 Income taxes 10,731 10,943 Pension and other postretirement benefit liabilities 114,010 101,413 Environmental costs (2) 118,619 104,253 Gas costs 1,917 22,355 Decoupling (3) 1,017 — COVID-19 deferrals and expenses, net 1,080 14,555 Other (5) 30,529 33,053 Total non-current 333,418 340,407 Other (NW Holdings) 25 25 Total non-current -NW Holdings $ 333,443 $ 340,432 Regulatory Liabilities In thousands 2023 2022 NW Natural: Current: Gas costs $ 6,375 $ 4,121 Unrealized gain on derivatives (1) 11,184 194,236 Decoupling (3) 7,612 14,026 Income taxes (6) 4,726 7,166 Asset optimization revenue sharing 31,583 26,368 Washington Climate Commitment Act proceeds 17,199 — Other (5) 6,233 2,636 Total current - NW Natural 84,912 248,553 Other (NW Holdings) 50 29 Total current - NW Holdings $ 84,962 $ 248,582 Non-current: Gas costs $ 8,556 $ 12,644 Unrealized gain on derivatives (1) 373 5,045 Decoupling (3) 2,118 3,814 Income taxes (6) 169,485 174,212 Accrued asset removal costs (7) 496,235 467,742 Asset optimization revenue sharing 2,325 8,401 Other (5) 15,855 16,741 Total non-current - NW Natural 694,947 688,599 Other (NW Holdings) 949 979 Total non-current -NW Holdings $ 695,896 $ 689,578 (1) Unrealized gains or losses on derivatives are non-cash items and, therefore, do not earn a rate of return or a carrying charge. These amounts are recoverable through natural gas distribution rates as part of the annual Purchased Gas Adjustment (PGA) mechanism when realized at settlement. (2) Refer to the Environmental Cost Deferral and Recovery table in Note 17 for a description of environmental costs. (3) This deferral represents the margin adjustment resulting from differences between actual and expected volumes. (4) Balance represents deferred net periodic benefit costs as approved by the OPUC. (5) Balances consist of deferrals and amortizations under approved regulatory mechanisms and typically earn a rate of return or carrying charge. (6) Balance represents excess deferred income tax benefits subject to regulatory flow-through. See Note 11. (7) Estimated costs of removal on certain regulated properties are collected through rates. See "Accounting Policies— Plant, Property, and Accrued Asset Removal Costs " below. The amortization period for NW Natural's regulatory assets and liabilities ranges from less than one year to an indeterminable period. Regulatory deferrals for gas costs payable are generally amortized over 12 months beginning each November 1 following the gas contract year during which the deferred gas costs are recorded. Similarly, most other regulatory deferred accounts are amortized over 12 months. However, certain regulatory account balances, such as income taxes, environmental costs, pension liabilities, and accrued asset removal costs, are large and tend to be amortized over longer periods once NW Natural has agreed upon an amortization period with the respective regulatory agency. We believe all costs incurred and deferred at December 31, 2023 are prudent. All regulatory assets are reviewed annually for recoverability, or more often if circumstances warrant. If we should determine that all or a portion of these regulatory assets no longer meet the criteria for continued application of regulatory accounting, then NW Holdings and NW Natural would be required to write-off the net unrecoverable balances in the period such determination is made. Regulatory interest income o f $6.5 million and $7.0 million and regulatory interest expense of $2.9 million and $2.0 million was recognized within other income (expense), net for the years ended December 31, 2023 and 2022, respectively. Environmental Regulatory Accounting See Note 17 for information about the SRRM and OPUC orders regarding implementation. New Accounting Standards NW Natural and NW Holdings consider the applicability and impact of all accounting standards updates (ASUs) issued by the Financial Accounting Standards Board (FASB). ASUs not listed below were assessed and determined to be either not applicable or are expected to have minimal impact on consolidated financial position or results of operations. Recently Issued Accounting Pronouncements JOINT VENTURE FORMATIONS. In August 2023, the FASB issued ASU 2023-05, which requires a joint venture to initially measure all contributions received upon its formation at fair value. The standard is effective for all joint venture entities with a formation date on or after January 1, 2025, with early adoption permitted. The adoption of this standard is not anticipated to have a material impact on our results of operations, liquidity or capital resources. SEGMENT REPORTING. In November 2023, the FASB issued ASU 2023-07, which requires additional disclosures about significant segment expenses. The disclosures are required beginning with our annual report for the year ending December 31, 2024. The adoption of this standard is not anticipated to have a material impact on our results of operations, liquidity or capital resources. IMPROVEMENTS TO INCOME TAX DISCLOSURES. In December 2023, the FASB issued ASU 2023-09, which requires additional disclosures about income taxes. The disclosures are required beginning with our annual report for the year ending December 31, 2025. The adoption of this standard is not anticipated to have a material impact on our results of operations, liquidity or capital resources. Recent Securities and Exchange Commission (SEC) Final Rules RECOVERY OF ERRONEOUSLY AWARDED COMPENSATION. In October 2022, the SEC adopted the final rule under SEC Release No. 33-11126, Listing Standards for Recovery of Erroneously Awarded Compensation, which directs the national securities exchanges and associations that list securities to establish listing standards requiring each issuer to develop and implement a clawback policy to recoup incentive-based compensation erroneously awarded to executive officers. The policy is included as an exhibit to our annual report for the year ending December 31, 2023. INSIDER TRADING ARRANGEMENTS. In December 2022, the SEC adopted the final rule under SEC Release No. 33-11138, Insider Trading Arrangements and Related Disclosures, which requires new disclosures regarding insider trading policies and procedures, the use of certain insider trading plans and director and executive compensation regarding equity compensation awards made close in time to disclosure of material nonpublic information. The policy will be included as an exhibit to our annual report for the year ending December 31, 2024. CYBERSECURITY DISCLOSURES. In July 2023, the SEC issued a final rule under SEC Release No. 33-11216, Cybersecurity Risk Management, Strategy, Governance, and Incident Disclosure, which requires new disclosures regarding material cybersecurity incidents and require periodic disclosures about registrant's processes to assess, identify, and manage material cybersecurity risks, management's role in assessing and managing material cybersecurity risks, and the board of directors' oversight of cybersecurity risks. The disclosures were required beginning with our annual report for the year ending December 31, 2023. Accounting Policies The accounting policies discussed below apply to both NW Holdings and NW Natural. Plant, Property, and Accrued Asset Removal Costs Plant and property are stated at cost, including capitalized labor, materials, and overhead. In accordance with regulatory accounting standards, the cost of acquiring and constructing long-lived plant and property generally includes an allowance for funds used during construction (AFUDC) or capitalized interest. AFUDC represents the regulatory financing cost incurred when debt and equity funds are used for construction (see “ AFUDC ” below). When constructed assets are subject to market-based rates rather than cost-based rates, the financing costs incurred during construction are included in capitalized interest in accordance with U.S. GAAP, not as regulatory financing costs under AFUDC. In accordance with long-standing regulatory treatment, our depreciation rates consist of three components: one based on the average service life of the asset, a second based on the estimated salvage value of the asset, and a third based on the asset’s estimated cost of removal. We collect, through rates, the estimated cost of removal on certain regulated properties through depreciation expense, with a corresponding offset to accumulated depreciation. These removal costs are non-legal obligations as defined by regulatory accounting guidance. Therefore, we have included these costs as non-current regulatory liabilities rather than as accumulated depreciation on our consolidated balance sheets. In the rate setting process, the liability for removal costs is treated as a reduction to the net rate base on which the NGD business has the opportunity to earn its allowed rate of return. The costs of NGD plant retired or otherwise disposed of are removed from NGD plant and charged to accumulated depreciation for recovery or refund through future rates. Gains from the sale of regulated assets are generally deferred and refunded to customers. For assets not related to NGD, we record a gain or loss upon the disposal of the property, and the gain or loss is recorded in operating income or loss in the consolidated statements of comprehensive income. The provision for depreciation of NGD property, plant, and equipment is recorded under the group method on a straight-line basis with rates computed in accordance with depreciation studies approved by regulatory authorities. The weighted-average depreciation rate for NGD assets in service was approximately 3.0% for 2023, 2022 and 2021, reflecting the approximate weighted-average economic life of the property. This includes 2023 weighted-average depreciation rates for the following asset categories: 2.5% for transmission and distribution plant, 2.2% for gas storage facilities, 6.7% for general plant, and 5.3% for intangible and other fixed assets. AFUDC. Certain additions to NGD plant include AFUDC, which represents the net cost of debt and equity funds used during construction. AFUDC is calculated using actual interest rates for debt and authorized rates for ROE, if applicable. If short-term debt balances are less than the total balance of construction work in progress, then a composite AFUDC rate is used to represent interest on all debt funds, shown as a reduction to interest charges, and on ROE funds, shown as other income. While cash is not immediately recognized from recording AFUDC, it is realized in future years through rate recovery resulting from the higher NGD cost of service. Our composite AFUDC rate was 7.5% in 2023, 2.8% in 2022, and 0.7% in 2021. IMPAIRMENT OF LONG-LIVED ASSETS. We review the carrying value of long-lived assets whenever events or changes in circumstances indicate the carrying amount of the assets may not be recoverable. Factors that would necessitate an impairment assessment of long-lived assets include a significant adverse change in the extent or manner in which the asset is used, a significant adverse change in legal factors or business climate that could affect the value of the asset, or a significant decline in the observable market value or expected future cash flows of the asset, among others. When such factors are present, we assess the recoverability by determining whether the carrying value of the asset will be recovered through expected future cash flows. An asset is determined to be impaired when the carrying value of the asset exceeds the expected undiscounted future cash flows from the use and eventual disposition of the asset. If an impairment is indicated, we record an impairment loss for the difference between the carrying value and the fair value of the long-lived assets. Fair value is estimated using appropriate valuation methodologies, which may include an estimate of discounted cash flows. Cash and Cash Equivalents Cash and cash equivalents include cash on hand plus highly liquid investment accounts with original maturity dates of three months or less. These investments are readily convertible to cash with fair value approximating cost. At December 31, 2023, NW Holdings had outstanding checks of $7.5 million, substantially all of which is recorded at NW Natural, and at December 31, 2022, NW Holdings had $5.8 million outstanding checks. These balances are included in accounts payable in the NW Holdings and NW Natural balance sheets. Restricted Cash Restricted cash is primarily comprised of funds from public purpose charges for programs that assist low-income customers with bill payments or energy efficiency. These balances are included in other current assets in the NW Holdings and NW Natural balance sheets. There were no transfers between restricted cash and cash and cash equivalents during the years ended December 31, 2023 and 2022. The following table provides a reconciliation of the cash, cash equivalents and restricted cash balances at NW Holdings as of December 31, 2023 and 2022: December 31, In thousands 2023 2022 Cash and cash equivalents $ 32,920 $ 29,270 Restricted cash included in other current assets 16,704 11,694 Cash, cash equivalents and restricted cash $ 49,624 $ 40,964 The following table provides a reconciliation of the cash, cash equivalents and restricted cash balances at NW Natural as of December 31, 2023 and 2022: December 31, In thousands 2023 2022 Cash and cash equivalents $ 19,841 $ 12,977 Restricted cash included in other current assets 16,679 11,694 Cash, cash equivalents and restricted cash $ 36,520 $ 24,671 Revenue Recognition and Accrued Unbilled Revenue Revenues, derived primarily from the sale and transportation of natural gas, are recognized upon delivery of gas or water, or service to customers. Revenues include accruals for gas or water delivered but not yet billed to customers based on estimates of deliveries from meter reading dates to month end (accrued unbilled revenue). Accrued unbilled revenue is dependent upon a number of factors that require management’s judgment, including total natural gas receipts and deliveries, customer use of natural gas or water by billing cycle, and weather factors. Accrued unbilled revenue is reversed the following month when actual billings occur. NW Holdings' accrued unbilled revenue at December 31, 2023 and 2022 was $83.1 million and $89.0 million, respectively, substantially all of which is accrued unbilled revenue at NW Natural. Revenues not related to NGD are derived primarily from Interstate Storage Services, asset management activities at the Mist gas storage facility, and other investments and business activities. At the Mist underground storage facility, revenues are primarily firm service revenues in the form of fixed monthly reservation charges. In addition, we also have asset management service revenue from an independent energy marketing company that optimizes commodity, storage, and pipeline capacity release transactions. Under this agreement, guaranteed asset management revenue is recognized using a straight-line, pro-rata methodology over the term of each contract. Revenues earned above the guaranteed amount are recognized as they are earned. Revenue Taxes Revenue-based taxes are primarily franchise taxes, which are collected from customers and remitted to taxing authorities. Revenue taxes are included in operating expenses in the statements of comprehensive income for NW Holdings and NW Natural. Revenue taxes at NW Holdings were $48.7 million, $41.8 million, and $34.7 million for 2023, 2022, and 2021, respectively. Accounts Receivable and Allowance for Uncollectible Accounts Accounts receivable consist primarily of amounts due for natural gas sales and transportation services to NGD customers, plus amounts due for gas storage services. NW Holdings and NW Natural establish allowances for uncollectible accounts (allowance) for trade receivables, including accrued unbilled revenue, based on the aging of receivables, collection experience of past due account balances including payment plans, and historical trends of write-offs as a percent of revenues. A specific allowance is established and recorded for large individual customer receivables when amounts are identified as unlikely to be partially or fully recovered. Inactive accounts are written-off against the allowance after they are 120 days past due or when deemed uncollectible. Differences between the estimated allowance and actual write-offs will occur based on a number of factors, including changes in economic conditions, customer creditworthiness, and natural gas prices. The allowance for uncollectible accounts is adjusted quarterly, as necessary, based on information currently available. ALLOWANCE FOR TRADE RECEIVABLES. The payment term of our NGD receivables is generally 15 days. For these short-term receivables, it is not expected that forecasted economic conditions would significantly affect the loss estimates under stable economic conditions. For extreme situations like a financial crisis, natural disaster, and the economic slowdown caused by the COVID-19 pandemic, we enhanced our review and analysis. For the residential and commercial uncollectible provision, we primarily followed our standard methodology, which includes assessing historical write-off trends and current information on delinquent accounts. Beginning October 1, 2022, new collection rules from the OPUC applied to residential and commercial customers. This included enhanced protections for low-income customers, a return to pre-pandemic time payment arrangements terms, revised disconnection rules during the heating season, and other items. As a result of these Oregon rule changes and our recent collection process experience, we augmented our provision review for accounts in the following categories: closed or inactive accounts aged less than 120 days, accounts on payment plans, and all other open accounts not on payment plans. For industrial accounts, we continue to assess the provision on an account-by-account basis with specific reserves taken as necessary. NW Natural will continue to closely monitor and evaluate our accounts receivable and the provision for uncollectible accounts. The following table presents the activity related to the NW Holdings provision for uncollectible accounts by pool, substantially all of which is related to NW Natural's accounts receivable: As of December 31, 2022 As of December 31, 2023 Year ended December 31, 2023 In thousands Beginning Balance Provision recorded, net of adjustments Write-offs recognized, net of recoveries Ending Balance Allowance for uncollectible accounts: Residential $ 2,155 $ 2,743 $ (2,501) $ 2,397 Commercial 400 454 (353) 501 Industrial 188 (122) (1) 65 Accrued unbilled and other 336 47 (118) 265 Total NW Natural 3,079 3,122 (2,973) 3,228 Other - NW Holdings 217 10 — 227 Total NW Holdings $ 3,296 $ 3,132 $ (2,973) $ 3,455 ALLOWANCE FOR NET INVESTMENTS IN SALES-TYPE LEASES. NW Natural currently holds two net investments in sales-type leases, with substantially all of the net investment balance related to the North Mist natural gas storage agreement with Portland General Electric (PGE) which is billed under an OPUC-approved rate schedule. See Note 7 for more information on the North Mist lease. Due to the nature of this service, PGE may recover the costs of the lease through general rate cases. Therefore, we expect the risk of loss due to the credit of this lessee to be remote. As such, no allowance for uncollectibility was recorded for our sales-type lease receivables. NW Natural will continue monitoring the credit health of the lessees and the overall economic environment, including the economic factors closely tied to the financial health of our current and future lessees. Inventories NGD gas inventories, which consist of natural gas in storage for NGD customers, are stated at the lower of weighted-average cost or net realizable value. The regulatory treatment of these inventories provides for cost recovery in customer rates. NGD gas inventories injected into storage are priced in inventory based on actual purchase costs, and those withdrawn from storage are charged to cost of gas during the period they are withdrawn at the weighted-average inventory cost. Gas storage inventories mainly consist of natural gas received as fuel-in-kind from storage customers. Gas storage inventories are valued at the lower of average cost or net realizable value. Cushion gas is not included in inventory balances, is recorded at original cost, and is classified as a long-term plant asset. Materials and supplies inventories consist of inventories both related to and unrelated to NGD and are stated at the lower of average cost or net realizable value. NW Natural's NGD and gas storage inventories totaled $47.2 million and $61.9 million at December 31, 2023 and 2022, respectively. At December 31, 2023 and 2022, NW Holdings' materials and supplies inventories, which are comprised primarily of NW Natural's materials and supplies, totaled $25.6 million and $23.5 million, respectively. During 2023 and 2022, NW Natural entered into certain agreements to purchase renewable thermal certificates (RTCs). RTCs are initially recorded at cost and subsequently assessed for impairment based on the lower-of-cost or market model. NW Natural's RTCs inventory totaled $0.5 million and $1.7 million at December 31, 2023 and 2022, respectively. Greenhouse Gas Allowances NW Natural is subject to greenhouse gas (GHG) emission reduction requirements under the Washington Climate Commitment Act (CCA) regulations and is likely to be subject to GHG emission reductions under a separate program in Oregon upon conclusion of the new ODEQ rulemaking. The new rulemaking was commenced upon the judicial invalidation of the prior rules promulgated by the ODEQ and is expected to take approximately 12 months. Under Washington's CCA, emission reduction compliance mechanisms include: 1) allowances distributed at no cost by the state, 2) purchasing allowances at state-run auctions or secondary markets, 3) purchasing carbon offsets, and 4) supplying alternative gaseous fuels, such as renewable natural gas and hydrogen. NW Natural will account for all purchased Washington allowances as inventory at the lower of cost or market. Any compliance instruments or allowances that are acquired through government allocations at no cost will be accounted for as inventory at no cost. As of December 31, 2023, NW Natural had $39.3 million of emissions allowances for compliance in Washington recorded as inventory. The CCA allows for the sale of compliance instruments or allowances, and as a result, should NW Natural sell these it will recognize revenue when title to the instrument or allowance is transferred to a counterparty, and NW Natural will recognize expense at the time of recognition of the related sale. In September and December 2023, NW Natural consigned no-cost allowances to Washington auctions and received $10.0 million and $7.1 million, respectively, in cash, which proceeds were recorded as a regulatory liability for the benefit of customers. We measure the compliance obligation, which is based on emissions, at the carrying value of inventory held plus the fair value of any additional emission allowances NW Natural would need to purchase to satisfy the obligations. Under the Washington program, NW Natural has recognized a $19.9 million liability as of December 31, 2023. We expect that the costs to comply with the Washington program will be recovered from utility customers through rates. As a result, NW Natural recognized $20.5 million of deferred costs as of December 31, 2023. Gas Reserves Gas reserves are payments to acquire and produce natural gas reserves. Gas reserves are stated at cost, adjusted for regulatory amortization, with the associated deferred tax benefits recorded as liabilities on the balance sheet. The current portion is calculated based on expected gas deliveries within the next fiscal year. NW Natural recognizes regulatory amortization of this asset on a volumetric basis calculated using the estimated gas reserves and the estimated therms extracted and sold each month. The amortization of gas reserves is recorded to cost of gas along with gas production revenues and production costs. See Note 13. Derivatives NW Natural's derivatives are measured at fair value and recognized as either assets or liabilities on the balance sheet. Changes in the fair value of the derivatives are recognized in earnings unless specific regulatory or hedge accounting criteria are met. Accounting for derivatives and hedges provides an exception for contracts intended for normal purchases and normal sales for which physical delivery is probable. In addition, certain derivative contracts are approved by regulatory authorities for recovery or refund through customer rates. Accordingly, the changes in fair value of these approved contracts are deferred as regulatory assets or liabilities pursuant to regulatory accounting principles. NW Natural's financial derivatives generally qualify for deferral under regulatory accounting. NW Natural's index-priced physical derivative contracts also qualify for regulatory deferral accounting treatment. Derivative contracts entered into for NGD requirements after the annual PGA rate has been set and maturing during the PGA year are subject to the PGA incentive sharing mechanism. In Oregon, NW Natural participates in a PGA sharing mechanism under which it is required to select either an 80% or 90% deferral of higher or lower gas costs such that the impact on current earnings from the gas cost sharing is either 20% or 10% of gas cost differences compared to PGA prices, respectively. For each of the PGA years in Oregon beginning November 1, 2023, 2022, and 2021, NW Natural selected the 90% deferral of gas cost differences. In Washington, 100% of the differences between the PGA prices and actual gas costs are deferred. See Note 15. NW Holdings and NW Natural have financial derivative policies that set forth guidelines for using selected derivative products to support prudent risk management strategies within designated parameters. NW Natural's objective for using derivatives is to decrease the volatility of gas prices, interest rates, and cash flows without speculative risk. The use of derivatives is permitted only after the risk exposures have been identified, are determined to exceed acceptable tolerance levels, and are determined necessary to support normal business activities. NW Natural does not enter into derivative instruments for trading purposes. All commodity and foreign exchange derivatives are currently held at NW Natural, and interest rate swaps are held at NW Holdings and NWN Water. Fair Value In accordance with fair value accounting, we use the following fair value hierarchy for determining inputs for our debt, pension plan assets, and derivative fair value measurements: • Level 1: Valuation is based on quoted prices for identical instruments traded in active markets; • Level 2: Valuation is based on quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market; and • Level 3: Valuation is generated from model-based techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect our own estimates of assumptions market participants would use in valuing the asset or liability. In addition, the fair value for certain pension trust investments is determined using Net Asset Value per share (NAV) as a practical expedient, and therefore they are not classified within the fair value hierarchy. These investments primarily consist of institutional investment products. When developing fair value measurements, it is our policy to use quoted market prices whenever available or to maximize the use of observable inputs and minimize the use of unobservable inputs when quoted market prices are not available. Fair values are primarily developed using industry-standard models that consider various inputs including: (a) quoted future prices for commodities; (b) forward currency prices; (c) time value; (d) volatility factors; (e) current market and contractual prices for underlying instruments; (f) market interest rates and yield curves; (g) credit spreads; and (h) other relevant economic measures. NW Natural considers liquid points for natural gas hedging to be those points for which there are regularly published prices in a nationally recognized publication or where the instruments are traded on an exchange. Goodwill and Business Combinations NW Holdings, through its wholly-owned subsidiary NWN Water and NWN Water's wholly-owned subsidiaries, has completed various acquisitions that resulted in the recognition of goodwill. Goodwill is measured as the excess of the acquisition-date fair value of the consideration transferred over the acquisition-date fair value of the net identifiable assets assumed. Adjustments are recorded during the measurement period to finalize the allocation of the purchase price. The carrying value of goodwill is reviewed annually during the fourth quarter, or whenever events or changes in circumstance indicate that such carrying values may not be recoverable. The goodwill assessment policy begins with a qualitative analysis in which events and circumstances are evaluated, including macroeconomic conditions, industry and market conditions, regulatory environments, and overall financial performance of the reporting unit. If the qualitative assessment indicates that the carrying value may be at risk of recoverability, a quantitative evaluation is performed to measure the carrying value of the goodwill against the fair value of the reporting unit. The reporting unit is determined primari |
Use of Estimates | Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles in the United States of America (U.S. GAAP) requires management to make estimates and assumptions that affect reported amounts in the consolidated financial statements and accompanying notes. Actual amounts could differ from those estimates, and changes would most likely be reported in future periods. Management believes the estimates and assumptions used are reasonable . |
Industry Regulation | Industry Regulation NW Holdings' principal business is to operate as a holding company for NW Natural and its other subsidiaries. NW Natural's principal business is the distribution of natural gas, which is regulated by the OPUC and WUTC. NW Natural also has natural gas storage services, which are regulated by the FERC, and to a certain extent by the OPUC and WUTC. Additionally, certain of NW Holdings' subsidiaries own water businesses, which are regulated by the public utility commission in the state in which the water utility is located, which is currently Oregon, Washington, Idaho, Texas and Arizona. Wastewater businesses, to the extent they are regulated, are generally regulated by the public utility commissions in the state in which the wastewater utility is located, which is currently Texas and Arizona. Accounting records and practices of the regulated businesses conform to the requirements and uniform system of accounts prescribed by these regulatory authorities in accordance with U.S. GAAP. The businesses in which customer rates are regulated have approved cost-based rates which are intended to allow such businesses to earn a reasonable return on invested capital. In applying regulatory accounting principles, NW Holdings and NW Natural capitalize or defer certain costs and revenues as regulatory assets and liabilities pursuant to orders of the applicable state public utility commission, which provide for the recovery of revenues or expenses from, or refunds to, utility customers in future periods, including a return or a carrying charge in certain cases. Amounts NW Natural deferred as regulatory assets and liabilities were as follows: Regulatory Assets In thousands 2023 2022 NW Natural: Current: Unrealized loss on derivatives (1) $ 98,661 $ 28,728 Gas costs 9,301 61,223 Environmental costs (2) 9,950 7,392 Decoupling (3) 2,288 — Pension balancing (4) 7,131 7,131 Income taxes 2,208 2,208 Washington Climate Commitment Act compliance 20,537 — COVID-19 deferrals and expenses, net 9,685 789 Other (5) 18,509 10,020 Total current $ 178,270 $ 117,491 Non-current: Unrealized loss on derivatives (1) $ 28,055 $ 20,838 Pension balancing (4) 27,460 32,997 Income taxes 10,731 10,943 Pension and other postretirement benefit liabilities 114,010 101,413 Environmental costs (2) 118,619 104,253 Gas costs 1,917 22,355 Decoupling (3) 1,017 — COVID-19 deferrals and expenses, net 1,080 14,555 Other (5) 30,529 33,053 Total non-current 333,418 340,407 Other (NW Holdings) 25 25 Total non-current -NW Holdings $ 333,443 $ 340,432 Regulatory Liabilities In thousands 2023 2022 NW Natural: Current: Gas costs $ 6,375 $ 4,121 Unrealized gain on derivatives (1) 11,184 194,236 Decoupling (3) 7,612 14,026 Income taxes (6) 4,726 7,166 Asset optimization revenue sharing 31,583 26,368 Washington Climate Commitment Act proceeds 17,199 — Other (5) 6,233 2,636 Total current - NW Natural 84,912 248,553 Other (NW Holdings) 50 29 Total current - NW Holdings $ 84,962 $ 248,582 Non-current: Gas costs $ 8,556 $ 12,644 Unrealized gain on derivatives (1) 373 5,045 Decoupling (3) 2,118 3,814 Income taxes (6) 169,485 174,212 Accrued asset removal costs (7) 496,235 467,742 Asset optimization revenue sharing 2,325 8,401 Other (5) 15,855 16,741 Total non-current - NW Natural 694,947 688,599 Other (NW Holdings) 949 979 Total non-current -NW Holdings $ 695,896 $ 689,578 (1) Unrealized gains or losses on derivatives are non-cash items and, therefore, do not earn a rate of return or a carrying charge. These amounts are recoverable through natural gas distribution rates as part of the annual Purchased Gas Adjustment (PGA) mechanism when realized at settlement. (2) Refer to the Environmental Cost Deferral and Recovery table in Note 17 for a description of environmental costs. (3) This deferral represents the margin adjustment resulting from differences between actual and expected volumes. (4) Balance represents deferred net periodic benefit costs as approved by the OPUC. (5) Balances consist of deferrals and amortizations under approved regulatory mechanisms and typically earn a rate of return or carrying charge. (6) Balance represents excess deferred income tax benefits subject to regulatory flow-through. See Note 11. (7) Estimated costs of removal on certain regulated properties are collected through rates. See "Accounting Policies— Plant, Property, and Accrued Asset Removal Costs " below. The amortization period for NW Natural's regulatory assets and liabilities ranges from less than one year to an indeterminable period. Regulatory deferrals for gas costs payable are generally amortized over 12 months beginning each November 1 following the gas contract year during which the deferred gas costs are recorded. Similarly, most other regulatory deferred accounts are amortized over 12 months. However, certain regulatory account balances, such as income taxes, environmental costs, pension liabilities, and accrued asset removal costs, are large and tend to be amortized over longer periods once NW Natural has agreed upon an amortization period with the respective regulatory agency. We believe all costs incurred and deferred at December 31, 2023 are prudent. All regulatory assets are reviewed annually for recoverability, or more often if circumstances warrant. If we should determine that all or a portion of these regulatory assets no longer meet the criteria for continued application of regulatory accounting, then NW Holdings and NW Natural would be required to write-off the net unrecoverable balances in the period such determination is made. Regulatory interest income o f $6.5 million and $7.0 million and regulatory interest expense of $2.9 million and $2.0 million was recognized within other income (expense), net for the years ended December 31, 2023 and 2022, respectively. Environmental Regulatory Accounting |
New Accounting Standards | New Accounting Standards NW Natural and NW Holdings consider the applicability and impact of all accounting standards updates (ASUs) issued by the Financial Accounting Standards Board (FASB). ASUs not listed below were assessed and determined to be either not applicable or are expected to have minimal impact on consolidated financial position or results of operations. Recently Issued Accounting Pronouncements JOINT VENTURE FORMATIONS. In August 2023, the FASB issued ASU 2023-05, which requires a joint venture to initially measure all contributions received upon its formation at fair value. The standard is effective for all joint venture entities with a formation date on or after January 1, 2025, with early adoption permitted. The adoption of this standard is not anticipated to have a material impact on our results of operations, liquidity or capital resources. SEGMENT REPORTING. In November 2023, the FASB issued ASU 2023-07, which requires additional disclosures about significant segment expenses. The disclosures are required beginning with our annual report for the year ending December 31, 2024. The adoption of this standard is not anticipated to have a material impact on our results of operations, liquidity or capital resources. IMPROVEMENTS TO INCOME TAX DISCLOSURES. In December 2023, the FASB issued ASU 2023-09, which requires additional disclosures about income taxes. The disclosures are required beginning with our annual report for the year ending December 31, 2025. The adoption of this standard is not anticipated to have a material impact on our results of operations, liquidity or capital resources. Recent Securities and Exchange Commission (SEC) Final Rules RECOVERY OF ERRONEOUSLY AWARDED COMPENSATION. In October 2022, the SEC adopted the final rule under SEC Release No. 33-11126, Listing Standards for Recovery of Erroneously Awarded Compensation, which directs the national securities exchanges and associations that list securities to establish listing standards requiring each issuer to develop and implement a clawback policy to recoup incentive-based compensation erroneously awarded to executive officers. The policy is included as an exhibit to our annual report for the year ending December 31, 2023. INSIDER TRADING ARRANGEMENTS. In December 2022, the SEC adopted the final rule under SEC Release No. 33-11138, Insider Trading Arrangements and Related Disclosures, which requires new disclosures regarding insider trading policies and procedures, the use of certain insider trading plans and director and executive compensation regarding equity compensation awards made close in time to disclosure of material nonpublic information. The policy will be included as an exhibit to our annual report for the year ending December 31, 2024. CYBERSECURITY DISCLOSURES. In July 2023, the SEC issued a final rule under SEC Release No. 33-11216, Cybersecurity Risk Management, Strategy, Governance, and Incident Disclosure, which requires new disclosures regarding material cybersecurity incidents and require periodic disclosures about registrant's processes to assess, identify, and manage material cybersecurity risks, management's role in assessing and managing material cybersecurity risks, and the board of directors' oversight of cybersecurity risks. The disclosures were required beginning with our annual report for the year ending December 31, 2023. |
Property, Plant and Accrued Asset Removal Costs | Plant, Property, and Accrued Asset Removal Costs Plant and property are stated at cost, including capitalized labor, materials, and overhead. In accordance with regulatory accounting standards, the cost of acquiring and constructing long-lived plant and property generally includes an allowance for funds used during construction (AFUDC) or capitalized interest. AFUDC represents the regulatory financing cost incurred when debt and equity funds are used for construction (see “ AFUDC ” below). When constructed assets are subject to market-based rates rather than cost-based rates, the financing costs incurred during construction are included in capitalized interest in accordance with U.S. GAAP, not as regulatory financing costs under AFUDC. In accordance with long-standing regulatory treatment, our depreciation rates consist of three components: one based on the average service life of the asset, a second based on the estimated salvage value of the asset, and a third based on the asset’s estimated cost of removal. We collect, through rates, the estimated cost of removal on certain regulated properties through depreciation expense, with a corresponding offset to accumulated depreciation. These removal costs are non-legal obligations as defined by regulatory accounting guidance. Therefore, we have included these costs as non-current regulatory liabilities rather than as accumulated depreciation on our consolidated balance sheets. In the rate setting process, the liability for removal costs is treated as a reduction to the net rate base on which the NGD business has the opportunity to earn its allowed rate of return. The costs of NGD plant retired or otherwise disposed of are removed from NGD plant and charged to accumulated depreciation for recovery or refund through future rates. Gains from the sale of regulated assets are generally deferred and refunded to customers. For assets not related to NGD, we record a gain or loss upon the disposal of the property, and the gain or loss is recorded in operating income or loss in the consolidated statements of comprehensive income. The provision for depreciation of NGD property, plant, and equipment is recorded under the group method on a straight-line basis with rates computed in accordance with depreciation studies approved by regulatory authorities. The weighted-average depreciation rate for NGD assets in service was approximately 3.0% for 2023, 2022 and 2021, reflecting the approximate weighted-average economic life of the property. This includes 2023 weighted-average depreciation rates for the following asset categories: 2.5% for transmission and distribution plant, 2.2% for gas storage facilities, 6.7% for general plant, and 5.3% for intangible and other fixed assets. AFUDC. Certain additions to NGD plant include AFUDC, which represents the net cost of debt and equity funds used during construction. AFUDC is calculated using actual interest rates for debt and authorized rates for ROE, if applicable. If short-term debt balances are less than the total balance of construction work in progress, then a composite AFUDC rate is used to represent interest on all debt funds, shown as a reduction to interest charges, and on ROE funds, shown as other income. While cash is not immediately recognized from recording AFUDC, it is realized in future years through rate recovery resulting from the higher NGD cost of service. Our composite AFUDC rate was 7.5% in 2023, 2.8% in 2022, and 0.7% in 2021. IMPAIRMENT OF LONG-LIVED ASSETS. We review the carrying value of long-lived assets whenever events or changes in circumstances indicate the carrying amount of the assets may not be recoverable. Factors that would necessitate an impairment assessment of long-lived assets include a significant adverse change in the extent or manner in which the asset is used, a significant adverse change in legal factors or business climate that could affect the value of the asset, or a significant decline in the observable market value or expected future cash flows of the asset, among others. When such factors are present, we assess the recoverability by determining whether the carrying value of the asset will be recovered through expected future cash flows. An asset is determined to be impaired when the carrying value of the asset exceeds the expected undiscounted future cash flows from the use and eventual disposition of the asset. If an impairment is indicated, we record an impairment loss for the difference between the carrying value and the fair value of the long-lived assets. Fair value is estimated using appropriate valuation methodologies, which may include an estimate of discounted cash flows. |
Schedule of Regulatory Liabilities | Regulatory Liabilities In thousands 2023 2022 NW Natural: Current: Gas costs $ 6,375 $ 4,121 Unrealized gain on derivatives (1) 11,184 194,236 Decoupling (3) 7,612 14,026 Income taxes (6) 4,726 7,166 Asset optimization revenue sharing 31,583 26,368 Washington Climate Commitment Act proceeds 17,199 — Other (5) 6,233 2,636 Total current - NW Natural 84,912 248,553 Other (NW Holdings) 50 29 Total current - NW Holdings $ 84,962 $ 248,582 Non-current: Gas costs $ 8,556 $ 12,644 Unrealized gain on derivatives (1) 373 5,045 Decoupling (3) 2,118 3,814 Income taxes (6) 169,485 174,212 Accrued asset removal costs (7) 496,235 467,742 Asset optimization revenue sharing 2,325 8,401 Other (5) 15,855 16,741 Total non-current - NW Natural 694,947 688,599 Other (NW Holdings) 949 979 Total non-current -NW Holdings $ 695,896 $ 689,578 (1) Unrealized gains or losses on derivatives are non-cash items and, therefore, do not earn a rate of return or a carrying charge. These amounts are recoverable through natural gas distribution rates as part of the annual Purchased Gas Adjustment (PGA) mechanism when realized at settlement. (2) Refer to the Environmental Cost Deferral and Recovery table in Note 17 for a description of environmental costs. (3) This deferral represents the margin adjustment resulting from differences between actual and expected volumes. (4) Balance represents deferred net periodic benefit costs as approved by the OPUC. (5) Balances consist of deferrals and amortizations under approved regulatory mechanisms and typically earn a rate of return or carrying charge. (6) Balance represents excess deferred income tax benefits subject to regulatory flow-through. See Note 11. (7) Estimated costs of removal on certain regulated properties are collected through rates. See "Accounting Policies— Plant, Property, and Accrued Asset Removal Costs |
Cash and Cash Equivalents | Cash and Cash Equivalents Cash and cash equivalents include cash on hand plus highly liquid investment accounts with original maturity dates of three months or less. These investments are readily convertible to cash with fair value approximating cost. At December 31, 2023, NW Holdings had outstanding checks of $7.5 million, substantially all of which is recorded at NW Natural, and at December 31, 2022, NW Holdings had $5.8 million outstanding checks. These balances are included in accounts payable in the NW Holdings and NW Natural balance sheets. Restricted Cash Restricted cash is primarily comprised of funds from public purpose charges for programs that assist low-income customers with bill payments or energy efficiency. These balances are included in other current assets in the NW Holdings and NW Natural balance sheets. There were no transfers between restricted cash and cash and cash equivalents during the years ended December 31, 2023 and 2022. The following table provides a reconciliation of the cash, cash equivalents and restricted cash balances at NW Holdings as of December 31, 2023 and 2022: December 31, In thousands 2023 2022 Cash and cash equivalents $ 32,920 $ 29,270 Restricted cash included in other current assets 16,704 11,694 Cash, cash equivalents and restricted cash $ 49,624 $ 40,964 The following table provides a reconciliation of the cash, cash equivalents and restricted cash balances at NW Natural as of December 31, 2023 and 2022: December 31, In thousands 2023 2022 Cash and cash equivalents $ 19,841 $ 12,977 Restricted cash included in other current assets 16,679 11,694 Cash, cash equivalents and restricted cash $ 36,520 $ 24,671 |
Revenue Recognition and Accrued Unbilled Revenue | Revenue Recognition and Accrued Unbilled Revenue Revenues, derived primarily from the sale and transportation of natural gas, are recognized upon delivery of gas or water, or service to customers. Revenues include accruals for gas or water delivered but not yet billed to customers based on estimates of deliveries from meter reading dates to month end (accrued unbilled revenue). Accrued unbilled revenue is dependent upon a number of factors that require management’s judgment, including total natural gas receipts and deliveries, customer use of natural gas or water by billing cycle, and weather factors. Accrued unbilled revenue is reversed the following month when actual billings occur. NW Holdings' accrued unbilled revenue at December 31, 2023 and 2022 was $83.1 million and $89.0 million, respectively, substantially all of which is accrued unbilled revenue at NW Natural. |
Revenue Taxes | Revenue Taxes |
Accounts Receivable and Allowance for Uncollectible Accounts | Accounts Receivable and Allowance for Uncollectible Accounts Accounts receivable consist primarily of amounts due for natural gas sales and transportation services to NGD customers, plus amounts due for gas storage services. NW Holdings and NW Natural establish allowances for uncollectible accounts (allowance) for trade receivables, including accrued unbilled revenue, based on the aging of receivables, collection experience of past due account balances including payment plans, and historical trends of write-offs as a percent of revenues. A specific allowance is established and recorded for large individual customer receivables when amounts are identified as unlikely to be partially or fully recovered. Inactive accounts are written-off against the allowance after they are 120 days past due or when deemed uncollectible. Differences between the estimated allowance and actual write-offs will occur based on a number of factors, including changes in economic conditions, customer creditworthiness, and natural gas prices. The allowance for uncollectible accounts is adjusted quarterly, as necessary, based on information currently available. ALLOWANCE FOR TRADE RECEIVABLES. The payment term of our NGD receivables is generally 15 days. For these short-term receivables, it is not expected that forecasted economic conditions would significantly affect the loss estimates under stable economic conditions. For extreme situations like a financial crisis, natural disaster, and the economic slowdown caused by the COVID-19 pandemic, we enhanced our review and analysis. For the residential and commercial uncollectible provision, we primarily followed our standard methodology, which includes assessing historical write-off trends and current information on delinquent accounts. Beginning October 1, 2022, new collection rules from the OPUC applied to residential and commercial customers. This included enhanced protections for low-income customers, a return to pre-pandemic time payment arrangements terms, revised disconnection rules during the heating season, and other items. As a result of these Oregon rule changes and our recent collection process experience, we augmented our provision review for accounts in the following categories: closed or inactive accounts aged less than 120 days, accounts on payment plans, and all other open accounts not on payment plans. For industrial accounts, we continue to assess the provision on an account-by-account basis with specific reserves taken as necessary. NW Natural will continue to closely monitor and evaluate our accounts receivable and the provision for uncollectible accounts. The following table presents the activity related to the NW Holdings provision for uncollectible accounts by pool, substantially all of which is related to NW Natural's accounts receivable: As of December 31, 2022 As of December 31, 2023 Year ended December 31, 2023 In thousands Beginning Balance Provision recorded, net of adjustments Write-offs recognized, net of recoveries Ending Balance Allowance for uncollectible accounts: Residential $ 2,155 $ 2,743 $ (2,501) $ 2,397 Commercial 400 454 (353) 501 Industrial 188 (122) (1) 65 Accrued unbilled and other 336 47 (118) 265 Total NW Natural 3,079 3,122 (2,973) 3,228 Other - NW Holdings 217 10 — 227 Total NW Holdings $ 3,296 $ 3,132 $ (2,973) $ 3,455 ALLOWANCE FOR NET INVESTMENTS IN SALES-TYPE LEASES. NW Natural currently holds two net investments in sales-type leases, with substantially all of the net investment balance related to the North Mist natural gas storage agreement with Portland General Electric (PGE) which is billed under an OPUC-approved rate schedule. See Note 7 for more information on the North Mist lease. Due to the nature of this service, PGE may recover the costs of the lease through general rate cases. Therefore, we expect the risk of loss due to the credit of this lessee to be remote. As such, no allowance for uncollectibility was recorded for our sales-type lease receivables. NW Natural will continue monitoring the credit health of the lessees and the overall economic environment, including the economic factors closely tied to the financial health of our current and future lessees. |
Inventories | Inventories NGD gas inventories, which consist of natural gas in storage for NGD customers, are stated at the lower of weighted-average cost or net realizable value. The regulatory treatment of these inventories provides for cost recovery in customer rates. NGD gas inventories injected into storage are priced in inventory based on actual purchase costs, and those withdrawn from storage are charged to cost of gas during the period they are withdrawn at the weighted-average inventory cost. Gas storage inventories mainly consist of natural gas received as fuel-in-kind from storage customers. Gas storage inventories are valued at the lower of average cost or net realizable value. Cushion gas is not included in inventory balances, is recorded at original cost, and is classified as a long-term plant asset. Materials and supplies inventories consist of inventories both related to and unrelated to NGD and are stated at the lower of average cost or net realizable value. NW Natural's NGD and gas storage inventories totaled $47.2 million and $61.9 million at December 31, 2023 and 2022, respectively. At December 31, 2023 and 2022, NW Holdings' materials and supplies inventories, which are comprised primarily of NW Natural's materials and supplies, totaled $25.6 million and $23.5 million, respectively. During 2023 and 2022, NW Natural entered into certain agreements to purchase renewable thermal certificates (RTCs). RTCs are initially recorded at cost and subsequently assessed for impairment based on the lower-of-cost or market model. NW Natural's RTCs inventory totaled $0.5 million and $1.7 million at December 31, 2023 and 2022, respectively. |
Gas Reserves | Gas Reserves Gas reserves are payments to acquire and produce natural gas reserves. Gas reserves are stated at cost, adjusted for regulatory amortization, with the associated deferred tax benefits recorded as liabilities on the balance sheet. The current portion is calculated based on expected gas deliveries within the next fiscal year. NW Natural recognizes regulatory amortization of this asset on a volumetric basis calculated using the estimated gas reserves and the estimated therms extracted and sold each month. The amortization of gas reserves is recorded to cost of gas along with gas production revenues and production costs. See Note 13. |
Derivatives | Derivatives NW Natural's derivatives are measured at fair value and recognized as either assets or liabilities on the balance sheet. Changes in the fair value of the derivatives are recognized in earnings unless specific regulatory or hedge accounting criteria are met. Accounting for derivatives and hedges provides an exception for contracts intended for normal purchases and normal sales for which physical delivery is probable. In addition, certain derivative contracts are approved by regulatory authorities for recovery or refund through customer rates. Accordingly, the changes in fair value of these approved contracts are deferred as regulatory assets or liabilities pursuant to regulatory accounting principles. NW Natural's financial derivatives generally qualify for deferral under regulatory accounting. NW Natural's index-priced physical derivative contracts also qualify for regulatory deferral accounting treatment. Derivative contracts entered into for NGD requirements after the annual PGA rate has been set and maturing during the PGA year are subject to the PGA incentive sharing mechanism. In Oregon, NW Natural participates in a PGA sharing mechanism under which it is required to select either an 80% or 90% deferral of higher or lower gas costs such that the impact on current earnings from the gas cost sharing is either 20% or 10% of gas cost differences compared to PGA prices, respectively. For each of the PGA years in Oregon beginning November 1, 2023, 2022, and 2021, NW Natural selected the 90% deferral of gas cost differences. In Washington, 100% of the differences between the PGA prices and actual gas costs are deferred. See Note 15. NW Holdings and NW Natural have financial derivative policies that set forth guidelines for using selected derivative products to support prudent risk management strategies within designated parameters. NW Natural's objective for using derivatives is to decrease the volatility of gas prices, interest rates, and cash flows without speculative risk. The use of derivatives is permitted only after the risk exposures have been identified, are determined to exceed acceptable tolerance levels, and are determined necessary to support normal business activities. NW Natural does not enter into derivative instruments for trading purposes. All commodity and foreign exchange derivatives are currently held at NW Natural, and interest rate swaps are held at NW Holdings and NWN Water. |
Fair Value | Fair Value In accordance with fair value accounting, we use the following fair value hierarchy for determining inputs for our debt, pension plan assets, and derivative fair value measurements: • Level 1: Valuation is based on quoted prices for identical instruments traded in active markets; • Level 2: Valuation is based on quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market; and • Level 3: Valuation is generated from model-based techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect our own estimates of assumptions market participants would use in valuing the asset or liability. In addition, the fair value for certain pension trust investments is determined using Net Asset Value per share (NAV) as a practical expedient, and therefore they are not classified within the fair value hierarchy. These investments primarily consist of institutional investment products. When developing fair value measurements, it is our policy to use quoted market prices whenever available or to maximize the use of observable inputs and minimize the use of unobservable inputs when quoted market prices are not available. Fair values are primarily developed using industry-standard models that consider various inputs including: (a) quoted future prices for commodities; (b) forward currency prices; (c) time value; (d) volatility factors; (e) current market and contractual prices for underlying instruments; (f) market interest rates and yield curves; (g) credit spreads; and (h) other relevant economic measures. NW Natural considers liquid points for natural gas hedging to be those points for which there are regularly published prices in a nationally recognized publication or where the instruments are traded on an exchange. |
Goodwill | Goodwill and Business Combinations NW Holdings, through its wholly-owned subsidiary NWN Water and NWN Water's wholly-owned subsidiaries, has completed various acquisitions that resulted in the recognition of goodwill. Goodwill is measured as the excess of the acquisition-date fair value of the consideration transferred over the acquisition-date fair value of the net identifiable assets assumed. Adjustments are recorded during the measurement period to finalize the allocation of the purchase price. The carrying value of goodwill is reviewed annually during the fourth quarter, or whenever events or changes in circumstance indicate that such carrying values may not be recoverable. The goodwill assessment policy begins with a qualitative analysis in which events and circumstances are evaluated, including macroeconomic conditions, industry and market conditions, regulatory environments, and overall financial performance of the reporting unit. If the qualitative assessment indicates that the carrying value may be at risk of recoverability, a quantitative evaluation is performed to measure the carrying value of the goodwill against the fair value of the reporting unit. The reporting unit is determined primarily based on current operating segments and the level of review provided by the Chief Operating Decision Maker (CODM) and/or segment management on the operating segment's financial results. Reporting units are evaluated periodically for changes in the corporate environment. As of December 31, 2023 and 2022, NW Holdings had goodwill of $163.3 million and $149.3 million, respectively. All of NW Holdings' goodwill was acquired through the business combinations completed by NWN Water and its wholly-owned subsidiaries. No impairment charges were recorded as a result of the fourth quarter goodwill impairment assessment. |
Income Taxes | Income Taxes We account for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the enactment date period unless, for NW Natural, a regulatory order specifies deferral of the effect of the change in tax rates over a longer period of time. For NW Natural, deferred income tax assets and liabilities are also recognized for temporary differences where the deferred income tax benefits or expenses have previously been flowed through in the ratemaking process of the NGD business. Regulatory tax assets and liabilities are recorded on these deferred tax assets and liabilities to the extent it is believed they will be recoverable from or refunded to customers in future rates. Investment tax credits associated with rate regulated plant additions are deferred for financial statement purposes and amortized over the estimated useful lives of the related plant. NW Holdings files consolidated or combined income tax returns that include NW Natural. Income tax expense is allocated on a separate company basis incorporating certain consolidated return considerations. Subsidiary income taxes payable or receivable are generally settled with NW Holdings, the common agent for income tax matters. |
Environmental Contingencies | Environmental Contingencies Loss contingencies are recorded as liabilities when it is probable a liability has been incurred and the amount of the loss is reasonably estimable in accordance with accounting standards for contingencies. Estimating probable losses requires an analysis of uncertainties that often depend upon judgments about potential actions by third parties. Accruals for loss contingencies are recorded based on an analysis of potential results. With respect to environmental liabilities and related costs, estimates are developed based on a review of information available from numerous sources, including completed studies and site specific negotiations. NW Natural's policy is to accrue the full amount of such liability when information is sufficient to reasonably estimate the amount of probable liability. When information is not available to reasonably estimate the probable liability, or when only the range of probable liabilities can be estimated and no amount within the range is more likely than another, it is our policy to accrue at the low end of the range. Accordingly, due to numerous uncertainties surrounding the course of environmental remediation and the preliminary nature of several site investigations, in some cases, it may not be possible to reasonably estimate the high end of the range of possible loss. In those cases, the nature of the potential loss and the fact that the high end of the range cannot be reasonably estimated is disclosed. See Note 17. |
Subsequent Events | Subsequent Events We monitor significant events occurring after the balance sheet date and prior to the issuance of the financial statements to determine the impacts, if any, of events on the financial statements to be issued. |
Equity Method Investments | Unconsolidated Affiliates NW Holdings, NW Natural and NWN Water have equity interests in businesses which we account for under the equity method as we do not exercise control of the major operating and financial policies. The business transactions with our equity method investments are not significant. We regularly assess the profitability and valuation of our investments for any potential impairment. See Note 13 . |
Emission Credits or Allowances, Policy | Greenhouse Gas Allowances NW Natural is subject to greenhouse gas (GHG) emission reduction requirements under the Washington Climate Commitment Act (CCA) regulations and is likely to be subject to GHG emission reductions under a separate program in Oregon upon conclusion of the new ODEQ rulemaking. The new rulemaking was commenced upon the judicial invalidation of the prior rules promulgated by the ODEQ and is expected to take approximately 12 months. Under Washington's CCA, emission reduction compliance mechanisms include: 1) allowances distributed at no cost by the state, 2) purchasing allowances at state-run auctions or secondary markets, 3) purchasing carbon offsets, and 4) supplying alternative gaseous fuels, such as renewable natural gas and hydrogen. NW Natural will account for all purchased Washington allowances as inventory at the lower of cost or market. Any compliance instruments or allowances that are acquired through government allocations at no cost will be accounted for as inventory at no cost. As of December 31, 2023, NW Natural had $39.3 million of emissions allowances for compliance in Washington recorded as inventory. The CCA allows for the sale of compliance instruments or allowances, and as a result, should NW Natural sell these it will recognize revenue when title to the instrument or allowance is transferred to a counterparty, and NW Natural will recognize expense at the time of recognition of the related sale. In September and December 2023, NW Natural consigned no-cost allowances to Washington auctions and received $10.0 million and $7.1 million, respectively, in cash, which proceeds were recorded as a regulatory liability for the benefit of customers. We measure the compliance obligation, which is based on emissions, at the carrying value of inventory held plus the fair value of any additional emission allowances NW Natural would need to purchase to satisfy the obligations. Under the Washington program, NW Natural has recognized a $19.9 million liability as of December 31, 2023. We expect that the costs to comply with the Washington program will be recovered from utility customers through rates. As a result, NW Natural recognized $20.5 million of deferred costs as of December 31, 2023. |
Internal Use Software, Policy | Cloud Computing Arrangements Implementation costs associated with its cloud computing arrangements are capitalized consistent with costs capitalized for internal-use software. Capitalized implementation costs are included in other assets in the consolidated balance sheets. The implementation costs are amortized over the term of the related hosting agreement, including renewal periods that are reasonably certain to be exercised. Amortization expense of implementation costs are recorded as operations and maintenance expenses in the consolidated statements of comprehensive income. The implementation costs are included within operating activities in the consolidated statements of cash flows. |
Schedule of Regulatory Assets | Amounts NW Natural deferred as regulatory assets and liabilities were as follows: Regulatory Assets In thousands 2023 2022 NW Natural: Current: Unrealized loss on derivatives (1) $ 98,661 $ 28,728 Gas costs 9,301 61,223 Environmental costs (2) 9,950 7,392 Decoupling (3) 2,288 — Pension balancing (4) 7,131 7,131 Income taxes 2,208 2,208 Washington Climate Commitment Act compliance 20,537 — COVID-19 deferrals and expenses, net 9,685 789 Other (5) 18,509 10,020 Total current $ 178,270 $ 117,491 Non-current: Unrealized loss on derivatives (1) $ 28,055 $ 20,838 Pension balancing (4) 27,460 32,997 Income taxes 10,731 10,943 Pension and other postretirement benefit liabilities 114,010 101,413 Environmental costs (2) 118,619 104,253 Gas costs 1,917 22,355 Decoupling (3) 1,017 — COVID-19 deferrals and expenses, net 1,080 14,555 Other (5) 30,529 33,053 Total non-current 333,418 340,407 Other (NW Holdings) 25 25 Total non-current -NW Holdings $ 333,443 $ 340,432 |
Accounts Receivable, Allowance for Credit Loss | The following table presents the activity related to the NW Holdings provision for uncollectible accounts by pool, substantially all of which is related to NW Natural's accounts receivable: As of December 31, 2022 As of December 31, 2023 Year ended December 31, 2023 In thousands Beginning Balance Provision recorded, net of adjustments Write-offs recognized, net of recoveries Ending Balance Allowance for uncollectible accounts: Residential $ 2,155 $ 2,743 $ (2,501) $ 2,397 Commercial 400 454 (353) 501 Industrial 188 (122) (1) 65 Accrued unbilled and other 336 47 (118) 265 Total NW Natural 3,079 3,122 (2,973) 3,228 Other - NW Holdings 217 10 — 227 Total NW Holdings $ 3,296 $ 3,132 $ (2,973) $ 3,455 |
Earnings Per Share (Tables)
Earnings Per Share (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Earnings Per Share [Abstract] | |
EPS Calculation [Table Text Block] | NW Holdings' diluted earnings or loss per share are calculated as follows: In thousands, except per share data 2023 2022 2021 Net income $ 93,868 $ 86,303 $ 78,666 Average common shares outstanding - basic 36,213 33,934 30,702 Additional shares for stock-based compensation plans (See Note 8) 52 50 50 Average common shares outstanding - diluted 36,265 33,984 30,752 Earnings per share of common stock: Basic $ 2.59 $ 2.54 $ 2.56 Diluted 2.59 2.54 2.56 Additional information: Anti-dilutive shares 1 2 7 |
Segment Information (Tables)
Segment Information (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Segment Reporting [Abstract] | |
Schedule of Segment Reporting Information, by Segment | The following table presents summary financial information concerning the reportable segment and other operations. In thousands NGD Other NW Natural Other NW Holdings 2023 Operating revenues $ 1,136,400 $ 22,223 $ 1,158,623 $ 38,852 $ 1,197,475 Depreciation 118,417 1,097 119,514 6,067 125,581 Income (loss) from operations 170,591 15,054 185,645 (704) 184,941 Net income (loss) 94,042 10,695 104,737 (10,869) 93,868 Capital expenditures 285,998 4,847 290,845 36,502 327,347 Total assets at December 31, 2023 4,458,117 53,260 4,511,377 355,715 4,867,092 2022 Operating revenues $ 989,752 $ 24,587 $ 1,014,339 $ 23,014 $ 1,037,353 Depreciation 111,871 1,086 112,957 3,750 116,707 Income (loss) from operations 152,839 16,535 169,374 (1,897) 167,477 Net income (loss) 79,690 11,874 91,564 (5,261) 86,303 Capital expenditures 315,979 2,707 318,686 19,916 338,602 Total assets at December 31, 2022 4,392,699 60,019 4,452,718 295,608 4,748,326 2021 Operating revenues $ 816,887 $ 26,170 $ 843,057 $ 17,343 $ 860,400 Depreciation 109,475 1,029 110,504 3,030 113,534 Income (loss) from operations 147,902 17,331 165,233 (2,116) 163,117 Net income (loss) 68,988 12,184 81,172 (2,506) 78,666 Capital expenditures 275,267 2,970 278,237 15,655 293,892 Total assets at December 31, 2021 3,846,112 52,260 3,898,372 166,232 4,064,604 |
Utility Margin | The following table presents additional segment information concerning NGD margin: In thousands 2023 2022 2021 NGD margin calculation: NGD operating revenues $ 1,117,498 $ 970,124 $ 797,800 Other regulated services 18,902 19,628 19,087 Total NGD operating revenues 1,136,400 989,752 816,887 Less: NGD cost of gas 500,061 429,861 292,538 Environmental remediation expense 12,899 12,389 9,938 Revenue taxes 48,432 41,627 34,600 NGD margin $ 575,008 $ 505,875 $ 479,811 |
Common Stock (Tables)
Common Stock (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Common Stock [Abstract] | |
Summary Of Common Stock Shares Issued And Outstanding Table | The following table summarizes the changes in the number of shares of NW Holdings' common stock issued and outstanding: In thousands Shares Balance, December 31, 2020 30,589 Sales to employees under ESPP 48 Stock-based compensation 49 Equity issuance 376 Sales to shareholders under DRPP 67 Balance, December 31, 2021 31,129 Sales to employees under ESPP 36 Stock-based compensation 42 Equity issuance 4,257 Sales to shareholders under DRPP 61 Balance, December 31, 2022 35,525 Sales to employees under ESPP 13 Stock-based compensation 39 Equity issuance 1,658 Sales to shareholders under DRPP 69 Shares issued in connection with business combinations 327 Balance, December 31, 2023 37,631 |
Revenue (Tables)
Revenue (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Revenue from Contract with Customer [Abstract] | |
Disaggregation of Revenue | The following table presents disaggregated revenue from continuing operations: Year ended December 31, 2023 In thousands NGD Other NW Natural Other NW Holdings Natural gas sales $ 1,109,223 $ — $ 1,109,223 $ — $ 1,109,223 Gas storage revenue, net — 12,041 12,041 — 12,041 Asset management revenue, net — 5,942 5,942 — 5,942 Appliance retail center revenue — 4,240 4,240 — 4,240 Other revenue 2,929 — 2,929 38,852 41,781 Revenue from contracts with customers 1,112,152 22,223 1,134,375 38,852 1,173,227 Alternative revenue 8,198 — 8,198 — 8,198 Leasing revenue 16,050 — 16,050 — 16,050 Total operating revenues $ 1,136,400 $ 22,223 $ 1,158,623 $ 38,852 $ 1,197,475 Year ended December 31, 2022 In thousands NGD Other NW Natural Other NW Holdings Natural gas sales $ 989,654 $ — $ 989,654 $ — $ 989,654 Gas storage revenue, net — 11,792 11,792 — 11,792 Asset management revenue, net — 6,965 6,965 — 6,965 Appliance retail center revenue — 5,830 5,830 — 5,830 Other revenue 2,510 — 2,510 23,014 25,524 Revenue from contracts with customers 992,164 24,587 1,016,751 23,014 1,039,765 Alternative revenue (19,605) — (19,605) — (19,605) Leasing revenue 17,193 — 17,193 — 17,193 Total operating revenues $ 989,752 $ 24,587 $ 1,014,339 $ 23,014 $ 1,037,353 Year ended December 31, 2021 In thousands NGD Other NW Natural Other NW Holdings Natural gas sales $ 783,027 $ — $ 783,027 $ — $ 783,027 Gas storage revenue, net — 10,830 10,830 — 10,830 Asset management revenue, net — 9,387 9,387 — 9,387 Appliance retail center revenue — 5,953 5,953 — 5,953 Other revenue 1,615 — 1,615 17,343 18,958 Revenue from contracts with customers 784,642 26,170 810,812 17,343 828,155 Alternative revenue 14,694 — 14,694 — 14,694 Leasing revenue 17,551 — 17,551 — 17,551 Total operating revenues $ 816,887 $ 26,170 $ 843,057 $ 17,343 $ 860,400 |
Leases (Tables)
Leases (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Leases [Abstract] | |
Lessee, Leases, Supplemental Cash Flow Information [Table Text Block] | Supplemental cash flow information related to leases was as follows: Year ended December 31, 2023 In thousands NW Natural Other NW Holdings Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 7,434 $ 176 $ 7,610 Finance cash flows from finance leases 369 — 369 Right of use assets obtained in exchange for lease obligations Operating leases $ 659 $ — $ 659 Finance leases 369 101 470 Year ended December 31, 2022 In thousands NW Natural Other NW Holdings Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 6,993 $ 64 $ 7,057 Finance cash flows from finance leases 524 — 524 Right of use assets obtained in exchange for lease obligations Operating leases $ 309 $ 668 $ 977 Finance leases 270 — 270 Year ended December 31, 2021 In thousands NW Natural Other NW Holdings Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 6,840 $ 58 $ 6,898 Finance cash flows from finance leases 801 — 801 Right of use assets obtained in exchange for lease obligations Operating leases $ 223 $ — $ 223 Finance leases 314 — 314 |
Lessee, Operating Lease, Liability, Maturity [Table Text Block] | Maturities of operating lease liabilities at December 31, 2023 were as follows: In thousands NW Natural Other NW Holdings 2024 $ 7,484 $ 183 $ 7,667 2025 7,362 176 7,538 2026 7,361 153 7,514 2027 7,538 107 7,645 2028 7,719 6 7,725 Thereafter 101,272 6 101,278 Total lease payments 138,736 631 139,367 Less: imputed interest 59,851 16 59,867 Total lease obligations 78,885 615 79,500 Less: current obligations 2,128 205 2,333 Long-term lease obligations $ 76,757 $ 410 $ 77,167 |
Lease, Cost [Table Text Block] | The components of lease expense, a portion of which is capitalized, were as follows: Year ended December 31, 2023 In thousands NW Natural Other NW Holdings Operating lease expense $ 7,244 $ 176 $ 7,420 Short-term lease expense 925 — 925 Year ended December 31, 2022 In thousands NW Natural Other NW Holdings Operating lease expense $ 7,003 $ 31 $ 7,034 Short-term lease expense 880 — 880 Year ended December 31, 2021 In thousands NW Natural Other NW Holdings Operating lease expense $ 6,859 $ 58 $ 6,917 Short-term lease expense 1,220 — 1,220 |
Operating Lease, Lease Income [Table Text Block] | The components of lease revenue at NW Natural were as follows: Year ended December 31, In thousands 2023 2022 2021 Lease revenue Operating leases $ 76 $ 74 $ 80 Sales-type leases 15,974 17,119 17,471 Total lease revenue $ 16,050 $ 17,193 $ 17,551 |
Lessor, Operating Lease, Payments to be Received, Maturity [Table Text Block] | Total future minimum lease payments to be received under non-cancelable leases at December 31, 2023 are as follows: In thousands Operating Sales-Type Total NW Natural: 2024 $ 603 $ 15,867 $ 16,470 2025 599 15,306 15,905 2026 36 14,901 14,937 2027 22 14,521 14,543 2028 — 13,983 13,983 Thereafter — 208,316 208,316 Total minimum lease payments $ 1,260 282,894 $ 284,154 Less: imputed interest 153,806 Total leases receivable $ 129,088 Other NW Holdings: 2024 $ 52 $ — $ 52 2025 53 — 53 2026 56 — 56 2027 57 — 57 2028 58 — 58 Thereafter 800 — 800 Total minimum lease payments $ 1,076 $ — $ 1,076 NW Holdings: 2024 $ 655 $ 15,867 $ 16,522 2025 652 15,306 15,958 2026 92 14,901 14,993 2027 79 14,521 14,600 2028 58 13,983 14,041 Thereafter 800 208,316 209,116 Total minimum lease payments $ 2,336 282,894 $ 285,230 Less: imputed interest 153,806 Total leases receivable $ 129,088 |
Operating Lease, Lease Asset and Liabilities [Table Text Block] | Supplemental balance sheet information related to operating leases as of December 31, 2023 is as follows: In thousands NW Natural Other NW Holdings Operating lease right of use assets $ 70,728 $ 580 $ 71,308 Operating lease liabilities - current liabilities $ 2,128 $ 205 $ 2,333 Operating lease liabilities - non-current liabilities 76,757 410 77,167 Total operating lease liabilities $ 78,885 $ 615 $ 79,500 Supplemental balance sheet information related to operating leases as of December 31, 2022 is as follows: In thousands NW Natural Other NW Holdings Operating lease right of use assets $ 72,720 $ 709 $ 73,429 Operating lease liabilities - current liabilities $ 1,363 $ 151 $ 1,514 Operating lease liabilities - non-current liabilities 78,345 620 78,965 Total operating lease liabilities $ 79,708 $ 771 $ 80,479 |
Stock-Based Compensation (Table
Stock-Based Compensation (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] | In thousands 2023 2022 2021 Operations and maintenance expense, for stock-based compensation $ 3,293 $ 2,877 $ 3,272 Income tax benefit (872) (762) (866) Net stock-based compensation effect on net income 2,421 2,115 2,406 Amounts capitalized for stock-based compensation $ 305 $ 351 $ 344 |
Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] | Number of RSUs Weighted - Nonvested, December 31, 2020 82,464 $ 59.40 Granted 38,160 49.16 Vested (31,733) 60.06 Forfeited (1,164) 46.82 Nonvested, December 31, 2021 87,727 54.87 Granted 48,212 46.50 Vested (33,054) 55.90 Forfeited (3,037) 56.34 Nonvested, December 31, 2022 99,848 50.44 Granted 45,532 48.24 Vested (36,393) 56.65 Forfeited (11,696) 49.98 Nonvested, December 31, 2023 97,291 $ 49.80 |
Share-based Payment Arrangement, Performance Shares, Outstanding Activity [Table Text Block] | The aggregate number of performance shares granted and outstanding at the target and maximum levels were as follows: Dollars in thousands Performance Share Awards Outstanding 2023 Performance Period Target Maximum Expense 2021-23 48,030 96,060 $ 1,581 2022-24 — — — 2023-25 — — — Total 48,030 96,060 $ 1,581 |
Long Term Incentive Plan [Member] | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Share-based Compensation Arrangements by Share-based Payment Award, Performance-Based Units, Vested and Expected to Vest [Table Text Block] | The following table summarizes performance share expense information: Dollars in thousands Shares (1) Expense During Award Year (2) Total Expense for Award Estimated award: 2021-2023 grant (3) 40,719 $ 1,581 $ 1,581 Actual award: 2020-2022 grant 29,472 $ 888 $ 888 2019-2021 grant 37,430 $ 1,323 $ 1,323 (1) In addition to common stock shares, a participant also receives a dividend equivalent cash payment equal to the number of shares of common stock received on the award payout multiplied by the aggregate cash dividends paid per share during the performance period. (2) Amount represents the expense recognized in the third year of the vesting period noted above. For the 2019-2021, 2020-2022, and 2021-2023 grants, mutual understanding of the award's key terms was established in the third year of the vesting period, triggering full expense recognition in 2021, 2022, and 2023, respectively. (3) This represents the estimated number of shares to be awarded as of December 31, 2023 as certain performance share measures have been achieved. Amounts are subject to change with final payout amounts authorized by the Board of Directors in February 2024. |
Debt (Tables)
Debt (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Debt Disclosure [Abstract] | |
Schedule of Maturities of Long-term Debt [Table Text Block] | Retirement of long-term debt for each of the annual periods through December 31, 2028 and thereafter are as follows: In thousands NW Natural Other (NW Holdings) NW Holdings 2024 $ — $ 150,868 $ 150,868 2025 30,000 824 30,824 2026 55,000 55,852 110,852 2027 64,700 881 65,581 2028 10,000 866 10,866 Thereafter 1,215,000 2,353 1,217,353 Total $ 1,374,700 $ 211,644 $ 1,586,344 |
Schedule of Debt [Table Text Block] | The following table presents debt outstanding at NW Natural as of December 31: In thousands 2023 2022 NW Natural: First Mortgage Bonds: 3.542% Series due 2023 $ — $ 50,000 5.620% Series due 2023 — 40,000 7.720% Series due 2025 20,000 20,000 6.520% Series due 2025 10,000 10,000 7.050% Series due 2026 20,000 20,000 3.211% Series due 2026 35,000 35,000 7.000% Series due 2027 20,000 20,000 2.822% Series due 2027 25,000 25,000 6.650% Series due 2027 19,700 19,700 6.650% Series due 2028 10,000 10,000 3.141% Series due 2029 50,000 50,000 7.740% Series due 2030 20,000 20,000 7.850% Series due 2030 10,000 10,000 5.820% Series due 2032 30,000 30,000 5.660% Series due 2033 40,000 40,000 5.750% Series due 2033 100,000 — 5.180% Series due 2034 80,000 — 5.250% Series due 2035 10,000 10,000 5.230% Series due 2038 50,000 — 4.000% Series due 2042 50,000 50,000 4.136% Series due 2046 40,000 40,000 3.685% Series due 2047 75,000 75,000 4.110% Series due 2048 50,000 50,000 3.869% Series due 2049 90,000 90,000 3.600% Series due 2050 150,000 150,000 3.078% Series due 2051 130,000 130,000 4.780% Series due 2052 140,000 140,000 5.430% Series due 2053 100,000 — Long-term debt, gross 1,374,700 1,134,700 Less: current maturities — 90,000 Total long-term debt $ 1,374,700 $ 1,044,700 |
Fair Value Of Long Term Debt Table [Text Block] | The following table provides an estimate of the fair value of long-term debt, including current maturities of long-term debt, using market prices in effect on the valuation date : December 31, In thousands 2023 2022 NW Natural: Gross long-term debt $ 1,374,700 $ 1,134,700 Unamortized debt issuance costs (9,968) (8,823) Carrying amount 1,364,732 1,125,877 Estimated fair value (1) 1,236,559 944,383 NW Holdings: Gross long-term debt $ 1,586,344 $ 1,345,851 Unamortized debt issuance costs (10,044) (8,987) Carrying amount 1,576,300 1,336,864 Estimated fair value (1) 1,447,941 1,148,395 (1) Estimated fair value does not include unamortized debt issuance costs. |
Pension and Other Postretirem_2
Pension and Other Postretirement Benefits Costs (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Retirement Benefits [Abstract] | |
Schedule of Defined Benefit Plans Disclosures | The following table provides a reconciliation of the changes in NW Natural's benefit obligations and fair value of plan assets, as applicable, for NW Natural's pension and other postretirement benefit plans, excluding the Retirement K Savings Plan, and a summary of the funded status and amounts recognized in NW Holdings' and NW Natural's consolidated balance sheets as of December 31: Postretirement Benefit Plans Pension Benefits Other Benefits In thousands 2023 2022 2023 2022 Reconciliation of change in benefit obligation: Obligation at January 1 $ 413,413 $ 542,618 $ 19,880 $ 27,223 Service cost 3,922 5,933 105 193 Interest cost 21,019 14,593 1,067 724 Net actuarial gain (loss) 15,066 (122,168) 2,208 (6,234) Benefits paid (27,970) (27,563) (1,793) (2,026) Obligation at December 31 425,450 413,413 21,467 19,880 Reconciliation of change in plan assets: Fair value of plan assets at January 1 280,304 399,217 — — Actual return on plan assets 28,841 (93,703) — — Employer contributions 2,269 2,353 1,793 2,026 Benefits paid (27,970) (27,563) (1,793) (2,026) Fair value of plan assets at December 31 283,444 280,304 — — Funded status at December 31 $ (142,006) $ (133,109) $ (21,467) $ (19,880) |
Schedule Of Amounts Recognized In Regulatory Assets Or Other Comprehensive Income Loss | The following table presents amounts realized through regulatory assets or in other comprehensive loss (income) for the years ended December 31: Regulatory Assets Other Comprehensive Loss (Income) Pension Benefits Other Postretirement Benefits Pension Benefits In thousands 2023 2022 2021 2023 2022 2021 2023 2022 2021 Net actuarial (gain) loss $ 10,318 $ 2,833 $ (32,258) $ 2,208 $ (6,234) $ (688) $ 1,630 $ (5,706) $ (812) Amortization of: Prior service credit — — — — 333 468 — — — Actuarial loss — (11,531) (21,250) — (426) (645) (713) (1,081) (1,225) Total $ 10,318 $ (8,698) $ (53,508) $ 2,208 $ (6,327) $ (865) $ 917 $ (6,787) $ (2,037) |
Schedule Of Defined Benefit Plan Amounts In AOCL And Regulatory Assets | The following table presents amounts recognized in regulatory assets and accumulated other comprehensive loss (AOCL) at December 31: Regulatory Assets AOCL Pension Benefits Other Postretirement Benefits Pension Benefits In thousands 2023 2022 2023 2022 2023 2022 Prior service credit $ — $ — $ — $ — $ — $ — Net actuarial loss (gain) 112,558 102,240 1,382 (826) 9,634 8,717 Total $ 112,558 $ 102,240 $ 1,382 $ (826) $ 9,634 $ 8,717 |
Schedule of Amounts Recognized in Other Comprehensive Income (Loss) | The following table presents amounts recognized by NW Holdings and NW Natural in AOCL and the changes in AOCL related to NW Natural's non-qualified employee benefit plans: Year ended December 31, In thousands 2023 2022 Beginning balance $ (6,414) $ (11,404) Amounts reclassified to AOCL (1,676) 5,706 Amounts reclassified from AOCL: Amortization of actuarial losses 558 1,081 Total reclassifications before tax (1,118) 6,787 Tax benefit (expense) 295 (1,797) Total reclassifications for the period (823) 4,990 Ending balance $ (7,237) $ (6,414) |
Schedule of Allocation of Plan Assets | The following table presents the Pension Plan asset target allocation at December 31, 2023: Asset Category Target Allocation Long government/credit 20 % U.S. large cap equity 18 Non-U.S. equity 18 Absolute return strategies 12 U.S. small/mid cap equity 10 Real estate funds 7 High yield bonds 5 Emerging markets equity 5 Emerging market debt 5 |
Schedule of Net Benefit Costs | The following table provides the components of net periodic benefit cost for NW Natural's pension and other postretirement benefit plans for the years ended December 31: Pension Benefits Other Postretirement Benefits In thousands 2023 2022 2021 2023 2022 2021 Service cost $ 3,922 $ 5,933 $ 6,981 $ 105 $ 193 $ 238 Interest cost 21,018 14,593 13,448 1,067 724 684 Expected return on plan assets (25,723) (25,698) (24,232) — — — Amortization of prior service credit — — — — (333) (468) Amortization of net actuarial loss 713 12,612 22,475 — 426 645 Net periodic (benefit) cost (70) 7,440 18,672 1,172 1,010 1,099 Amount allocated to construction (1,684) (2,621) (3,015) (36) (76) (93) Net periodic (benefit) cost charged to expense (1,754) 4,819 15,657 1,136 934 1,006 Amortization of regulatory balancing account 7,131 7,131 7,131 — — — Net amount charged to expense $ 5,377 $ 11,950 $ 22,788 $ 1,136 $ 934 $ 1,006 |
Sensitivity Analysis Of Retirement Benefit Costs and Benefit Obligations | The following table provides the assumptions used in measuring periodic benefit costs and benefit obligations for the years ended December 31: Pension Benefits Other Postretirement Benefits 2023 2022 2021 2023 2022 2021 Assumptions for net periodic benefit cost: Weighted-average discount rate 5.14 % 2.71 % 2.40 % 5.19 % 2.72 % 2.34 % Rate of increase in compensation 4.00-5.00% 3.50 % 3.50 % n/a n/a n/a Expected long-term rate of return 7.50 % 7.00 % 7.25 % n/a n/a n/a Assumptions for year-end funded status: Weighted-average discount rate 4.98 % 5.18 % 2.71 % 4.98 % 5.19 % 2.72 % Rate of increase in compensation (1) 4.00-4.73% 4.00-6.00% 3.50 % n/a n/a n/a Expected long-term rate of return 7.50 % 7.50 % 7.00 % n/a n/a n/a |
Defined Benefit Plan Estimated Future Employer Contributions Benefit Payments and Estimated Future Payments | The following table provides information regarding employer contributions and benefit payments for NW Natural's Pension Plan, non-qualified pension plans, and other postretirement benefit plans for the years ended December 31, and estimated future contributions and payments: In thousands Pension Benefits Other Benefits Employer Contributions: 2022 $ 2,353 $ 2,026 2023 2,269 1,793 2024 (estimated) 22,850 3,233 Benefit Payments: 2021 $ 25,371 $ 2,050 2022 27,563 2,026 2023 27,970 1,793 Estimated Future Benefit Payments: 2024 $ 27,288 $ 3,233 2025 36,313 1,652 2026 27,979 1,620 2027 28,300 1,608 2028 28,604 1,583 2029-2033 145,652 7,440 |
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis | The following tables present the fair value of NW Natural's Pension Plan assets, including outstanding receivables and liabilities, of NW Natural's retirement trust fund: In thousands December 31, 2023 Investments Level 1 Level 2 Level 3 Non-Published NAV (1) Total US equity $ — $ — $ — $ 73,910 $ 73,910 International / Global equity 27,730 — — 63,767 91,497 Liability hedging — — — 98,408 98,408 Opportunistic — — — 17,148 17,148 Cash and cash equivalents — — — 2,480 2,480 Total investments $ 27,730 $ — $ — $ 255,713 $ 283,443 December 31, 2022 Investments Level 1 Level 2 Level 3 Non-Published NAV (1) Total US equity $ — $ — $ — $ 68,729 $ 68,729 International / Global equity 26,677 — — 63,827 90,504 Liability hedging — — — 94,823 94,823 Opportunistic — — — 23,903 23,903 Cash and cash equivalents — — — 2,345 2,345 Total investments $ 26,677 $ — $ — $ 253,627 $ 280,304 December 31, 2023 2022 Receivables: Accrued interest and dividend income $ 10,698 $ 7,703 Total receivables 10,698 7,703 Liabilities: Due to broker for securities purchased (10,698) (7,701) Total investment in retirement trust $ 283,443 $ 280,306 (1) The fair value for these investments is determined using Net Asset Value per share (NAV) as of December 31, as a practical expedient, and therefore they are not classified within the fair value hierarchy. These investments primarily consist of institutional investment products, for which the NAV is generally not publicly available. |
Income Tax (Tables)
Income Tax (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Income Tax Disclosure [Abstract] | |
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] | The following table provides a reconciliation between income taxes calculated at the statutory federal tax rate and the provision for income taxes reflected in the NW Holdings and NW Natural statements of comprehensive income or loss for December 31: NW Holdings NW Natural Dollars in thousands 2023 2022 2021 2023 2022 2021 Income taxes at federal statutory rate $ 26,508 $ 24,241 $ 22,275 $ 29,486 $ 25,746 $ 22,996 Increase (decrease): State income tax, net of federal 10,875 10,139 9,962 11,510 10,504 10,150 Differences required to be flowed-through by regulatory commissions (3,976) (4,748) (4,655) (3,972) (4,746) (4,738) Other, net (1,045) (502) (176) (1,352) (468) (75) Total provision for income taxes $ 32,362 $ 29,130 $ 27,406 $ 35,672 $ 31,036 $ 28,333 Effective tax rate 25.6% 25.2% 25.8% 25.4% 25.3% 25.9% |
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] | The provision for current and deferred income taxes consists of the following at December 31: NW Holdings NW Natural In thousands 2023 2022 2021 2023 2022 2021 Current Federal $ 13,496 $ 5,172 $ 6,508 $ 20,512 $ 7,442 $ 7,570 State 9,901 6,551 6,281 12,304 7,307 7,540 Total current income taxes 23,397 11,723 12,789 32,816 14,749 15,110 Deferred Federal 5,100 11,124 8,289 591 10,298 7,915 State 3,865 6,283 6,328 2,265 5,989 5,308 Total deferred income taxes 8,965 17,407 14,617 2,856 16,287 13,223 Income tax provision $ 32,362 $ 29,130 $ 27,406 $ 35,672 $ 31,036 $ 28,333 |
Schedule of Deferred Tax Assets and Liabilities [Table Text Block] | The following table summarizes the tax effect of significant items comprising NW Holdings and NW Natural's deferred income tax balances recorded at December 31: NW Holdings NW Natural In thousands 2023 2022 2023 2022 Deferred tax liabilities: Plant and property $ 350,802 $ 326,326 $ 340,042 $ 320,121 Leases receivable 35,635 36,873 35,635 36,873 Pension and postretirement obligations 24,830 22,973 24,830 22,973 Income tax regulatory asset 12,939 13,152 12,939 13,152 Lease right of use assets 21,002 21,272 20,849 21,084 Other Intangibles 528 — — — Other 4,432 17,050 4,620 17,314 Total deferred income tax liabilities 450,168 437,646 438,915 431,517 Deferred income tax assets: Income tax regulatory liability 46,372 48,270 46,120 48,018 Lease liabilities 21,047 21,306 20,884 21,102 Other intangible assets — 1,947 — — Net operating losses and credits carried forward 76 101 44 44 Total deferred income tax assets 67,495 71,624 67,048 69,164 Total net deferred income tax liabilities $ 382,673 $ 366,022 $ 371,867 $ 362,353 |
Property, Plant and Equipment (
Property, Plant and Equipment (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Public Utilities, Property, Plant and Equipment [Abstract] | |
Major Classifications Of Property, Plant And Equipment And Accumulated Depreciation [Text Block] | The following table sets forth the major classifications of property, plant, and equipment and accumulated depreciation of continuing operations at December 31: In thousands 2023 2022 NW Natural: NGD plant in service $ 4,206,455 $ 3,992,676 NGD construction work in progress 105,166 78,897 Less: Accumulated depreciation 1,159,367 1,115,690 NGD plant, net 3,152,254 2,955,883 Other plant in service 71,175 70,368 Other construction work in progress 10,963 6,606 Less: Accumulated depreciation 22,595 21,541 Other plant, net 59,543 55,433 Total property, plant, and equipment $ 3,211,797 $ 3,011,316 Other (NW Holdings): Other plant in service $ 147,040 $ 92,979 Other construction work in progress 15,810 20,040 Less: Accumulated depreciation 16,593 9,935 Other plant, net 146,257 103,084 NW Holdings: Total property, plant, and equipment $ 3,358,054 $ 3,114,400 NW Natural: Capital expenditures in accrued liabilities $ 24,168 $ 24,584 NW Holdings: Capital expenditures in accrued liabilities $ 27,879 $ 25,318 |
Investments (Tables)
Investments (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Investments [Abstract] | |
Investment | The following table summarizes other investments at December 31: NW Holdings NW Natural In thousands 2023 2022 2023 2022 Investments in life insurance policies $ 45,713 $ 49,358 $ 45,713 $ 49,358 Investments in gas reserves, non-current 20,893 22,970 20,893 22,970 Investments in unconsolidated affiliates 36,345 23,376 19,539 7,782 Total other investments $ 102,951 $ 95,704 $ 86,145 $ 80,110 |
Derivative Instruments (Tables)
Derivative Instruments (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
Schedule of Notional Amounts of Outstanding Derivative Positions | The following table presents the absolute notional amounts related to open positions on NW Natural derivative instruments: At December 31, In thousands 2023 2022 Natural gas (in therms): Financial 948,425 852,435 Physical 571,610 463,254 Foreign exchange $ 11,926 $ 7,617 |
Income Statement Presentation of Derivative Instruments | The following table reflects the income statement presentation for the unrealized gains and losses from NW Natural's derivative instruments: December 31, 2023 December 31, 2022 In thousands Natural gas commodity Foreign exchange Natural gas commodity Foreign exchange Benefit (expense) to cost of gas $ (131,833) $ 168 $ 119,935 $ (165) Operating revenues (expense) — — — — Amounts deferred to regulatory accounts on balance sheet 131,833 (168) (119,935) 165 Total gain (loss) in pre-tax earnings $ — $ — $ — $ — |
Commitments and Contingencies (
Commitments and Contingencies (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Commitments and Contingencies Disclosure [Abstract] | |
Long-term Purchase Commitment | The aggregate amounts of these agreements at NW Natural were as follows at December 31, 2023: In thousands Gas Purchase Agreements (1) Pipeline Pipeline 2024 $ 303,682 $ 78,907 $ 7,543 2025 34,457 81,114 3,455 2026 34,586 66,972 — 2027 33,830 67,123 — 2028 33,980 63,812 — Thereafter 208,426 377,175 — Total 648,961 735,103 10,998 Less: Amount representing interest 96,491 183,620 373 Total at present value $ 552,470 $ 551,483 $ 10,625 |
Environmental Matters (Tables)
Environmental Matters (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Environmental Remediation Obligations [Abstract] | |
Schedule of Environmental Loss Contingencies by Site | The following table summarizes information regarding liabilities related to environmental sites, which are recorded in other current liabilities and other noncurrent liabilities in NW Natural's balance sheet at December 31: Current Liabilities Non-Current Liabilities In thousands 2023 2022 2023 2022 Portland Harbor site: Gasco/Siltronic Sediments $ 12,428 $ 9,744 $ 42,550 $ 42,120 Other Portland Harbor 3,035 2,634 11,270 11,270 Gasco/Siltronic Upland site 16,304 16,067 34,235 35,457 Front Street site 687 457 939 879 Oregon Steel Mills — — 179 179 Total $ 32,454 $ 28,902 $ 89,173 $ 89,905 |
Environmental Regulatory Table | The following table presents information regarding the total regulatory asset deferred as of December 31: In thousands 2023 2022 Deferred costs and interest (1) $ 57,758 $ 47,666 Accrued site liabilities (2) 121,575 118,763 Insurance proceeds and interest (50,764) (54,784) Total regulatory asset deferral (1) 128,569 111,645 Current regulatory assets (3) 9,950 7,392 Long-term regulatory assets (3) 118,619 104,253 (1) Includes pre-review and post-review deferred costs, amounts currently in amortization, and interest, net of amounts collected from customers. (2) Excludes 3.3% of the Front Street site liability as the OPUC only allows recovery of 96.7% of costs for those sites allocable to Oregon, including those that historically served only Oregon customers. Amounts excluded from regulatory assets were $53 thousand in 2023 and $43 thousand in 2022. (3) Environmental costs relate to specific sites approved for regulatory deferral by the OPUC and WUTC. In Oregon, NW Natural earns a carrying charge on cash amounts paid, whereas amounts accrued but not yet paid do not earn a carrying charge until expended. It also accrues a carrying charge on insurance proceeds for amounts owed to customers. In Washington, neither the cash paid nor insurance proceeds received accrue a carrying charge. Current environmental costs represent remediation costs management expects to collect from customers in the next 12 months. Amounts included in this estimate are still subject to a prudence and earnings test review by the OPUC and do not include the $5.0 million tariff rider. The amounts allocable to Oregon are recoverable through NGD rates, subject to an earnings test. See " Oregon SRRM " below. |
Condensed Financials Standalo_2
Condensed Financials Standalone Holdco NW Holdings Financial Statements (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Condensed Income Statements, Captions [Line Items] | |
Condensed Income Statement [Table Text Block] | NORTHWEST NATURAL HOLDING COMPANY CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (PARENT COMPANY ONLY) Year Ended December 31, In thousands 2023 2022 2021 Operating expenses: Operations and maintenance $ 5,145 $ 3,828 $ 4,837 Total operating expenses 5,145 3,828 4,837 Loss from operations (5,145) (3,828) (4,837) Earnings from investment in subsidiaries, net of tax 106,267 92,727 83,072 Other income (expense), net (1,156) 60 (143) Interest expense, net 10,022 4,967 982 Income before income taxes 89,944 83,992 77,110 Income tax benefit (3,924) (2,311) (1,556) Net income 93,868 86,303 78,666 Other comprehensive income (loss) from subsidiaries, net of tax (868) 5,108 1,498 Unrealized gain on interest rate swap, net of tax 104 11 — Comprehensive income $ 93,104 $ 91,422 $ 80,164 See Notes to Condensed Financial Statements |
Condensed Balance Sheet [Table Text Block] | NORTHWEST NATURAL HOLDING COMPANY CONDENSED BALANCE SHEETS (PARENT COMPANY ONLY) As of December 31, In thousands 2023 2022 Assets: Current assets: Cash and cash equivalents $ 1,011 $ 7,280 Receivables from affiliates 15,596 9,967 Other current assets 4,160 2,895 Total current assets 20,767 20,142 Non-current assets: Investments in subsidiaries 1,456,449 1,357,599 Other investments 32 14 Deferred tax assets 513 520 Other non-current assets 367 486 Total non-current assets 1,457,361 1,358,619 Total assets $ 1,478,128 $ 1,378,761 Liabilities and equity: Current liabilities: Short-term debt $ 73,000 $ 88,000 Current maturities of long-term debt 99,992 — Accounts payable 968 402 Payables to affiliates 19,897 14,665 Other current liabilities 433 295 Total current liabilities 194,290 103,362 Long-term debt — 99,958 Total equity 1,283,838 1,175,441 Total liabilities and equity $ 1,478,128 $ 1,378,761 See Notes to Condensed Financial Statements |
Condensed Cash Flow Statement [Table Text Block] | NORTHWEST NATURAL HOLDING COMPANY CONDENSED STATEMENTS OF CASH FLOWS (PARENT COMPANY ONLY) Year Ended December 31, In thousands 2023 2022 2021 Operating activities: Net income $ 93,868 $ 86,303 $ 78,666 Adjustments to reconcile net income to cash used in operations: Equity in earnings of subsidiaries, net of tax (106,267) (92,727) (83,072) Cash dividends received from subsidiaries 92,375 62,710 56,057 Deferred income taxes (31) (141) (212) Other 164 142 119 Changes in assets and liabilities: Receivables from affiliates (5,629) (7,787) 12,558 Income and other taxes (491) 8,161 1,299 Accounts payable 6,314 (2,499) 3,342 Interest accrued 103 156 57 Other, net (380) (211) (313) Cash provided by operating activities 80,026 54,107 68,501 Investing activities: Contributions to subsidiaries (76,310) (241,497) (142,405) Return of capital from subsidiaries 3,350 — 26,000 Cash used in investing activities (72,960) (241,497) (116,405) Financing activities: Proceeds from common stock issued, net 66,495 208,561 17,501 Long-term debt issued — 100,000 — Changes in other short-term debt, net (15,000) (56,000) 71,000 Cash dividend payments on common stock (67,340) (62,771) (55,919) Other 2,510 4,615 4,320 Cash (used in) provided by financing activities (13,335) 194,405 36,902 (Decrease) increase in cash and cash equivalents (6,269) 7,015 (11,002) Cash, cash equivalents and restricted cash, beginning of period 7,280 265 11,267 Cash, cash equivalents and restricted cash, end of period $ 1,011 $ 7,280 $ 265 See Notes to Condensed Financial Statements |
Valuation Allowances and Rese_2
Valuation Allowances and Reserves (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Entity Information [Line Items] | |
Summary of Valuation Allowance | NORTHWEST NATURAL HOLDING COMPANY SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E Additions Deductions In thousands (year ended December 31) Balance at beginning of period Charged to costs and expenses Charged to other accounts Net write-offs Balance at end of period 2023 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 3,296 $ 2,869 $ 263 $ 2,973 $ 3,455 2022 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 2,018 $ 1,081 $ 1,810 $ 1,613 $ 3,296 2021 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 3,219 $ 724 $ (219) $ 1,706 $ 2,018 |
Northwest Natural Gas Company [Member] | |
Entity Information [Line Items] | |
Summary of Valuation Allowance | NORTHWEST NATURAL GAS COMPANY SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E Additions Deductions In thousands (year ended December 31) Balance at beginning of period Charged to costs and expenses Charged to other accounts Net write-offs Balance at end of period 2023 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 3,079 $ 2,859 $ 263 $ 2,973 $ 3,228 2022 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 1,962 $ 920 $ 1,810 $ 1,613 $ 3,079 2021 Reserves deducted in balance sheet from assets to which they apply: Allowance for uncollectible accounts $ 3,107 $ 780 $ (219) $ 1,706 $ 1,962 |
- Narrative (Details)
- Narrative (Details) $ in Thousands | 3 Months Ended | 12 Months Ended | |||
Dec. 31, 2023 USD ($) numberOfLeases | Dec. 31, 2023 USD ($) numberOfLeases | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | |
Industry Regulation [Abstract] | |||||
Regulatory Assets, Noncurrent | $ 333,443 | $ 333,443 | $ 340,432 | ||
COVID-19 Impact [Abstract] | |||||
Regulatory Assets, Noncurrent | 333,443 | $ 333,443 | $ 340,432 | ||
Property, Plant and Accrued Asset Removal Costs [Abstract] | |||||
Weighted Average Depreciation Rates Transmission Distribution | 2.50% | ||||
Weighted Average Depreciation Rates Gas Storage | 2.20% | ||||
Weighted Average Depreciation Rates General Plant | 6.70% | ||||
Weighted Average Depreciation Rates Intangible Other | 5.30% | ||||
Public Utilities, AFUDC, Rate | 7.50% | 2.80% | 0.70% | ||
Cash and Cash Equivalents [Abstract] | |||||
Cash and cash equivalents | $ 32,920 | $ 32,920 | $ 29,270 | ||
Restricted Cash and Cash Equivalents, Current, Statement of Financial Position [Extensible Enumeration] | Other current assets | Other current assets | Other current assets | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | $ 49,624 | $ 49,624 | $ 40,964 | $ 27,120 | $ 35,454 |
Revenue Recognition [Abstract] | |||||
Accrued unbilled revenue | 83,138 | 83,138 | 89,048 | ||
Revenue Taxes [Abstract] | |||||
Utilities Operating Expense, Taxes | 48,700 | 41,800 | 34,700 | ||
Inventory Disclosure [Abstract] | |||||
Inventory, Raw Materials and Supplies, Net of Reserves | 25,600 | 25,600 | 23,500 | ||
Goodwill and Intangible Assets Disclosure [Abstract] | |||||
Goodwill | 163,344 | 163,344 | 149,283 | ||
Goodwill and Intangible Asset Impairment | 0 | ||||
Income Tax Disclosure [Abstract] | |||||
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued | $ 0 | $ 0 | |||
Allowance for Credit Loss [Abstract] | |||||
Number of Net Investments in Sales-Type Leases | numberOfLeases | 2 | 2 | |||
Inactive Account, Period Outstanding Prior to Write-off | 120 days | 120 days | |||
General Payment Term of NGD Receivables | 15 days | 15 days | |||
Age of Closed or Inactive Accounts | 120 days | 120 days | |||
Accounts Payable [Member] | |||||
Cash and Cash Equivalents [Abstract] | |||||
Bank Overdrafts | $ 7,500 | $ 7,500 | 5,800 | ||
Northwest Natural Gas Company [Member] | |||||
Industry Regulation [Abstract] | |||||
Regulatory Liability, Amortization Period | 12 months | 12 months | |||
Regulatory Asset, Amortization Period | 12 months | 12 months | |||
Regulatory Assets, Noncurrent | $ 333,418 | $ 333,418 | 340,407 | ||
COVID-19 Impact [Abstract] | |||||
Regulatory Assets, Noncurrent | 333,418 | 333,418 | 340,407 | ||
Cash and Cash Equivalents [Abstract] | |||||
Cash and cash equivalents | $ 19,841 | $ 19,841 | $ 12,977 | ||
Restricted Cash and Cash Equivalents, Current, Statement of Financial Position [Extensible Enumeration] | Other current assets | Other current assets | Other current assets | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | $ 36,520 | $ 36,520 | $ 24,671 | $ 20,832 | $ 15,739 |
Revenue Recognition [Abstract] | |||||
Accrued unbilled revenue | 81,524 | 81,524 | 87,482 | ||
Inventory Disclosure [Abstract] | |||||
Inventory - Gas | 47,200 | 47,200 | 61,900 | ||
Energy Related Inventory, Renewable Thermal Credits | 500 | 500 | 1,700 | ||
Allowance for Credit Loss [Abstract] | |||||
Accounts Receivable, Allowance for Credit Loss, Recovery | 2,973 | ||||
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease) | 3,122 | ||||
Accounts Receivable, Allowance for Credit Loss | 3,228 | $ 3,228 | $ 3,079 | ||
Northwest Natural Gas Company [Member] | Oregon [Member] | |||||
Industry Regulation [Abstract] | |||||
Purchased Gas Adjustment Percentage | 90% | 90% | 90% | ||
Investments | |||||
PGA deferral rate | 90% | 90% | 90% | ||
Northwest Natural Gas Company [Member] | Oregon [Member] | Minimum [Member] | |||||
Industry Regulation [Abstract] | |||||
Purchased Gas Adjustment Percentage | 80% | ||||
Investments | |||||
PGA deferral rate | 80% | ||||
Impact on earnings from gas cost sharing | 10% | ||||
Northwest Natural Gas Company [Member] | Oregon [Member] | Maximum [Member] | |||||
Industry Regulation [Abstract] | |||||
Purchased Gas Adjustment Percentage | 90% | ||||
Investments | |||||
PGA deferral rate | 90% | ||||
Impact on earnings from gas cost sharing | 20% | ||||
Northwest Natural Gas Company [Member] | WASHINGTON | |||||
Industry Regulation [Abstract] | |||||
Purchased Gas Adjustment Percentage | 100% | 100% | 100% | ||
Investments | |||||
PGA deferral rate | 100% | 100% | 100% | ||
Northwest Natural Gas Company [Member] | Industrial | |||||
Allowance for Credit Loss [Abstract] | |||||
Accounts Receivable, Allowance for Credit Loss, Recovery | $ 1 | ||||
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease) | (122) | ||||
Accounts Receivable, Allowance for Credit Loss | 65 | 65 | $ 188 | ||
Northwest Natural Gas Company [Member] | Accrued unbilled and other | |||||
Allowance for Credit Loss [Abstract] | |||||
Accounts Receivable, Allowance for Credit Loss, Recovery | 118 | ||||
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease) | 47 | ||||
Accounts Receivable, Allowance for Credit Loss | 265 | 265 | 336 | ||
Northwest Natural Gas Company [Member] | Residential | |||||
Allowance for Credit Loss [Abstract] | |||||
Accounts Receivable, Allowance for Credit Loss, Recovery | 2,501 | ||||
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease) | 2,743 | ||||
Accounts Receivable, Allowance for Credit Loss | 2,397 | 2,397 | 2,155 | ||
Northwest Natural Gas Company [Member] | Commercial | |||||
Allowance for Credit Loss [Abstract] | |||||
Accounts Receivable, Allowance for Credit Loss, Recovery | 353 | ||||
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease) | 454 | ||||
Accounts Receivable, Allowance for Credit Loss | 501 | 501 | 400 | ||
Northwest Natural Gas Company [Member] | COVID-19 Related Costs | |||||
Industry Regulation [Abstract] | |||||
Regulatory Assets, Noncurrent | 1,080 | 1,080 | 14,555 | ||
COVID-19 Impact [Abstract] | |||||
Regulatory Assets, Noncurrent | 1,080 | 1,080 | 14,555 | ||
Northwest Holdings Other [Member] | |||||
Allowance for Credit Loss [Abstract] | |||||
Accounts Receivable, Allowance for Credit Loss, Recovery | 0 | ||||
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease) | 10 | ||||
Accounts Receivable, Allowance for Credit Loss | 227 | 227 | 217 | ||
Northwest Holdings [Member] | |||||
Allowance for Credit Loss [Abstract] | |||||
Accounts Receivable, Allowance for Credit Loss, Recovery | 2,973 | ||||
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease) | 3,132 | ||||
Accounts Receivable, Allowance for Credit Loss | $ 3,455 | $ 3,455 | 3,296 | ||
Asset Recoverable Gas Costs [Member] | Northwest Natural Gas Company [Member] | |||||
Industry Regulation [Abstract] | |||||
Regulatory Liability, Amortization Period | 12 months | 12 months | |||
Other Nonoperating Income (Expense) [Member] | |||||
Industry Regulation [Abstract] | |||||
Other Nonoperating Income | $ 6,500 | 7,000 | |||
Other Nonoperating Expense | $ 2,900 | $ 2,000 | |||
Natural Gas Distribution [Member] | |||||
Property, Plant and Accrued Asset Removal Costs [Abstract] | |||||
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 3% | 3% | 3% | ||
Weighted-average depreciation rate, assets in service | 3% | 3% | 3% | ||
Natural Gas Distribution [Member] | Operating Segments [Member] | |||||
Revenue Taxes [Abstract] | |||||
Utilities Operating Expense, Taxes | $ 48,432 | $ 41,627 | $ 34,600 |
Significant Accounting Polici_2
Significant Accounting Policies - Regulatory Asset Disclosure (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2023 | Dec. 31, 2022 | |
Regulatory Assets [Line Items] | ||
Regulatory Assets, Current | $ 178,270 | $ 117,491 |
Regulatory Assets, Noncurrent | 333,443 | 340,432 |
Sales-type Lease, Net Investment in Lease, Allowance for Credit Loss | 0 | |
Inventory, Emissions Allowances | 39,300 | |
Other [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Noncurrent | 25 | 25 |
Northwest Natural Gas Company [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Current | 178,270 | 117,491 |
Regulatory Assets, Noncurrent | $ 333,418 | 340,407 |
Regulatory Asset, Amortization Period | 12 months | |
Accounts Receivable, Allowance for Credit Loss | $ 3,228 | 3,079 |
Accounts Receivable, Allowance for Credit Loss, Recovery | 2,973 | |
Northwest Natural Gas Company [Member] | Residential | ||
Regulatory Assets [Line Items] | ||
Accounts Receivable, Allowance for Credit Loss | 2,397 | 2,155 |
Accounts Receivable, Allowance for Credit Loss, Recovery | 2,501 | |
Northwest Natural Gas Company [Member] | Unrealized loss on derivatives [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Current | 98,661 | 28,728 |
Regulatory Assets, Noncurrent | 28,055 | 20,838 |
Northwest Natural Gas Company [Member] | Gas costs [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Current | 9,301 | 61,223 |
Regulatory Assets, Noncurrent | 1,917 | 22,355 |
Northwest Natural Gas Company [Member] | Environmental costs [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Current | 9,950 | 7,392 |
Regulatory Assets, Noncurrent | 118,619 | 104,253 |
Northwest Natural Gas Company [Member] | Decoupling [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Current | 2,288 | 0 |
Regulatory Assets, Noncurrent | 1,017 | 0 |
Northwest Natural Gas Company [Member] | Income taxes [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Current | 2,208 | 2,208 |
Regulatory Assets, Noncurrent | 10,731 | 10,943 |
Northwest Natural Gas Company [Member] | Pension balancing [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Current | 7,131 | 7,131 |
Regulatory Assets, Noncurrent | 27,460 | 32,997 |
Northwest Natural Gas Company [Member] | Pension and other postretirement benefit liabilities [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Noncurrent | 114,010 | 101,413 |
Northwest Natural Gas Company [Member] | Other [Member] | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Current | 18,509 | 10,020 |
Regulatory Assets, Noncurrent | 30,529 | 33,053 |
Northwest Natural Gas Company [Member] | COVID-19 Related Costs | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Current | 9,685 | 789 |
Regulatory Assets, Noncurrent | 1,080 | 14,555 |
Northwest Natural Gas Company [Member] | Washington Climate Commitment Act compliance | ||
Regulatory Assets [Line Items] | ||
Regulatory Assets, Current | 20,537 | 0 |
Northwest Holdings Other [Member] | ||
Regulatory Assets [Line Items] | ||
Accounts Receivable, Allowance for Credit Loss | 227 | 217 |
Accounts Receivable, Allowance for Credit Loss, Recovery | 0 | |
Northwest Holdings [Member] | ||
Regulatory Assets [Line Items] | ||
Accounts Receivable, Allowance for Credit Loss | 3,455 | $ 3,296 |
Accounts Receivable, Allowance for Credit Loss, Recovery | $ 2,973 |
Significant Accounting Polici_3
Significant Accounting Policies - Regulatory Liability Disclosure (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | |
Dec. 31, 2023 | Sep. 30, 2023 | Dec. 31, 2022 | |
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | $ 84,962 | $ 248,582 | |
Regulatory Liability, Noncurrent | 695,896 | 689,578 | |
CCI Deferred Costs | 20,500 | ||
Oregon [Member] | |||
Regulatory Liabilities [Line Items] | |||
CCI Credits Liability | 19,900 | ||
Washington Climate Commitment Act Allowances | |||
Regulatory Liabilities [Line Items] | |||
Proceeds from Other Operating Activities | 7,100 | $ 10,000 | |
Other [Member] | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | 50 | 29 | |
Regulatory Liability, Noncurrent | 949 | 979 | |
Accrued asset removal costs [Member] | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Noncurrent | 496,200 | 467,700 | |
Northwest Natural Gas Company [Member] | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | 84,912 | 248,553 | |
Regulatory Liability, Noncurrent | 694,947 | 688,599 | |
Northwest Natural Gas Company [Member] | Gas costs [Member] | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | 6,375 | 4,121 | |
Regulatory Liability, Noncurrent | 8,556 | 12,644 | |
Northwest Natural Gas Company [Member] | Unrealized gain on derivatives [Member] | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | 11,184 | 194,236 | |
Regulatory Liability, Noncurrent | 373 | 5,045 | |
Northwest Natural Gas Company [Member] | Decoupling [Member] | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | 7,612 | 14,026 | |
Regulatory Liability, Noncurrent | 2,118 | 3,814 | |
Northwest Natural Gas Company [Member] | Other [Member] | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | 6,233 | 2,636 | |
Regulatory Liability, Noncurrent | 15,855 | 16,741 | |
Northwest Natural Gas Company [Member] | Income taxes [Member] | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | 4,726 | 7,166 | |
Regulatory Liability, Noncurrent | 169,485 | 174,212 | |
Regulatory Liabilities | 174,200 | 181,400 | |
Northwest Natural Gas Company [Member] | Accrued asset removal costs [Member] | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Noncurrent | 496,235 | 467,742 | |
Northwest Natural Gas Company [Member] | Asset Optimization Revenue Sharing | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | 31,583 | 26,368 | |
Regulatory Liability, Noncurrent | 2,325 | 8,401 | |
Northwest Natural Gas Company [Member] | Washington Climate Commitment Act compliance | |||
Regulatory Liabilities [Line Items] | |||
Regulatory Liability, Current | 17,199 | $ 0 | |
Regulatory Liabilities | $ 7,100 | $ 10,000 |
Significant Accounting Polici_4
Significant Accounting Policies Significant Accounting Policies - Leases ASU 2016-02 (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||
Operating Lease, Right-of-Use Asset | $ 71,308 | $ 73,429 |
Northwest Natural Gas Company [Member] | ||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||
Operating Lease, Right-of-Use Asset | $ 70,728 | $ 72,720 |
Earnings Per Share (Details)
Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Earnings Per Share [Abstract] | |||
Net income from continuing operations | $ 93,868 | $ 86,303 | $ 78,666 |
Net income | $ 93,868 | $ 86,303 | $ 78,666 |
Average common shares outstanding: | |||
Average common shares outstanding - basic (in shares) | 36,213 | 33,934 | 30,702 |
Additional shares for stock-based compensation plans | 52 | 50 | 50 |
Average common shares outstanding - diluted (in shares) | 36,265 | 33,984 | 30,752 |
Earnings per share of common stock: | |||
Basic (in dollars per share) | $ 2.59 | $ 2.54 | $ 2.56 |
Diluted (in dollars per share) | 2.59 | 2.54 | 2.56 |
Earnings (loss) per share of common stock | |||
Basic (in dollars per share) | 2.59 | 2.54 | 2.56 |
Diluted (in dollars per share) | $ 2.59 | $ 2.54 | $ 2.56 |
Antidilutive shares | 1 | 2 | 7 |
Segment Information - Narrative
Segment Information - Narrative (Details) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | |
Segment Reporting Information [Line Items] | |||
Assets | $ 4,867,092 | $ 4,748,326 | |
Operating Segments [Member] | |||
Segment Reporting Information [Line Items] | |||
Number of Reportable Segments | 1 | ||
Operating Segments [Member] | Natural Gas Distribution [Member] | |||
Segment Reporting Information [Line Items] | |||
Assets | $ 4,458,117 | $ 4,392,699 | $ 3,846,112 |
Northwest Holdings and Northwest Natural [Member] | Operating Segments [Member] | |||
Segment Reporting Information [Line Items] | |||
Segment Reporting, Disclosure of Major Customers | No | ||
Oregon [Member] | Northwest Holdings and Northwest Natural [Member] | Natural Gas Distribution [Member] | |||
Segment Reporting Information [Line Items] | |||
Percent Of Pre Tax Income From Gas Storage Retained When The Costs Of The Capacity Are Not In Utility Rates | 80% | ||
Percent Of Pre Tax Income From Gas Storage Retained When The Costs Of The Capacity Are In Utility Rates | 10% | ||
Percent Of Pre Tax Income From Gas Storage Credited To Deferred Regulatory Account | 20% | ||
Percent Of Pre Tax Income From Gas Storage Credited To Deferred Regulatory Account When In Rates | 90% | ||
Customer Total [Member] | Geographic Concentration Risk [Member] | Oregon [Member] | Natural Gas Distribution [Member] | |||
Segment Reporting Information [Line Items] | |||
Concentration Risk, Percentage | 88% | ||
Customer Total [Member] | Geographic Concentration Risk [Member] | WASHINGTON | Natural Gas Distribution [Member] | |||
Segment Reporting Information [Line Items] | |||
Concentration Risk, Percentage | 12% | ||
Volumes Delivered [Member] | Volumes Delivered [Member] | Residential and Commerical Customers [Member] | Natural Gas Distribution [Member] | |||
Segment Reporting Information [Line Items] | |||
Concentration Risk, Percentage | 60% | ||
Gross Profit Margin [Member] | Residential and Commerical Customers [Member] | Residential and Commerical Customers [Member] | Natural Gas Distribution [Member] | |||
Segment Reporting Information [Line Items] | |||
Concentration Risk, Percentage | 90% |
Segment Information - Schedule
Segment Information - Schedule of Summarized Financial Information by Segment (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Segment Reporting Information [Line Items] | |||
Operating revenues | $ 1,197,475 | $ 1,037,353 | $ 860,400 |
Depreciation | 125,581 | 116,707 | 113,534 |
Income (loss) from operations | 184,941 | 167,477 | 163,117 |
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent | 93,868 | 86,303 | 78,666 |
Total assets | 4,867,092 | 4,748,326 | |
Other Northwest Natural [Member] | Corporate, Non-Segment [Member] | |||
Segment Reporting Information [Line Items] | |||
Operating revenues | 22,223 | 24,587 | 26,170 |
Depreciation | 1,097 | 1,086 | 1,029 |
Income (loss) from operations | 15,054 | 16,535 | 17,331 |
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent | 10,695 | 11,874 | 12,184 |
Total assets | 53,260 | 60,019 | 52,260 |
Segment, Expenditure, Addition to Long-Lived Assets | 4,847 | 2,707 | 2,970 |
Northwest Natural Gas Company [Member] | Operating Segments [Member] | |||
Segment Reporting Information [Line Items] | |||
Operating revenues | 1,158,623 | 1,014,339 | 843,057 |
Depreciation | 119,514 | 112,957 | 110,504 |
Income (loss) from operations | 185,645 | 169,374 | 165,233 |
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent | 104,737 | 91,564 | 81,172 |
Total assets | 4,511,377 | 4,452,718 | 3,898,372 |
Segment, Expenditure, Addition to Long-Lived Assets | 290,845 | 318,686 | 278,237 |
Northwest Holdings Other [Member] | Corporate, Non-Segment [Member] | |||
Segment Reporting Information [Line Items] | |||
Operating revenues | 38,852 | 23,014 | 17,343 |
Depreciation | 6,067 | 3,750 | 3,030 |
Income (loss) from operations | (704) | (1,897) | (2,116) |
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent | (10,869) | (5,261) | (2,506) |
Total assets | 355,715 | 295,608 | 166,232 |
Segment, Expenditure, Addition to Long-Lived Assets | 36,502 | 19,916 | 15,655 |
Natural Gas Distribution [Member] | Operating Segments [Member] | |||
Segment Reporting Information [Line Items] | |||
Operating revenues | 1,136,400 | 989,752 | 816,887 |
Depreciation | 118,417 | 111,871 | 109,475 |
Income (loss) from operations | 170,591 | 152,839 | 147,902 |
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent | 94,042 | 79,690 | 68,988 |
Total assets | 4,458,117 | 4,392,699 | 3,846,112 |
Segment, Expenditure, Addition to Long-Lived Assets | 285,998 | 315,979 | 275,267 |
Northwest Natural Gas Company [Member] | |||
Segment Reporting Information [Line Items] | |||
Operating revenues | 1,158,623 | 1,014,339 | 843,057 |
Depreciation | 119,514 | 112,957 | 110,504 |
Income (loss) from operations | 185,645 | 169,374 | 165,233 |
Total assets | 4,511,377 | 4,452,718 | |
Northwest Natural Gas Company [Member] | Other Northwest Natural [Member] | Corporate, Non-Segment [Member] | |||
Segment Reporting Information [Line Items] | |||
Operating revenues | 22,223 | 24,587 | 26,170 |
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | |||
Segment Reporting Information [Line Items] | |||
Operating revenues | 1,158,623 | 1,014,339 | 843,057 |
Northwest Natural Gas Company [Member] | Natural Gas Distribution [Member] | Operating Segments [Member] | |||
Segment Reporting Information [Line Items] | |||
Operating revenues | 1,136,400 | 989,752 | 816,887 |
Parent Company [Member] | |||
Segment Reporting Information [Line Items] | |||
Operating revenues | 1,197,475 | 1,037,353 | 860,400 |
Depreciation | 125,581 | 116,707 | 113,534 |
Income (loss) from operations | 184,941 | 167,477 | 163,117 |
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent | 93,868 | 86,303 | 78,666 |
Total assets | 4,867,092 | 4,748,326 | 4,064,604 |
Segment, Expenditure, Addition to Long-Lived Assets | $ 327,347 | $ 338,602 | $ 293,892 |
Segment Information - Additiona
Segment Information - Additional Segment Information (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Segment Reporting Information [Line Items] | |||
Operating revenues | $ 1,197,475 | $ 1,037,353 | $ 860,400 |
Cost of gas | 499,837 | 429,635 | 292,314 |
Environmental remediation | 12,899 | 12,389 | 9,938 |
Revenue taxes | 48,700 | 41,800 | 34,700 |
Northwest Natural Gas Company [Member] | |||
Segment Reporting Information [Line Items] | |||
Operating revenues | 1,158,623 | 1,014,339 | 843,057 |
Cost of gas | 500,061 | 429,861 | 292,538 |
Environmental remediation | $ 12,899 | 12,389 | 9,938 |
Major Customer Threshold, Percent of Operating Revenues | 10% | ||
Operating Segments [Member] | Natural Gas Distribution [Member] | |||
Segment Reporting Information [Line Items] | |||
NGD operating revenues | $ 1,117,498 | 970,124 | 797,800 |
Other regulated services | 18,902 | 19,628 | 19,087 |
Operating revenues | 1,136,400 | 989,752 | 816,887 |
Cost of gas | 500,061 | 429,861 | 292,538 |
Environmental remediation | 12,899 | 12,389 | 9,938 |
Revenue taxes | 48,432 | 41,627 | 34,600 |
NGD margin | 575,008 | 505,875 | 479,811 |
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | |||
Segment Reporting Information [Line Items] | |||
Operating revenues | $ 1,136,400 | $ 989,752 | $ 816,887 |
Common Stock - Narrative (Detai
Common Stock - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Shares Authorized (in shares) | 100,000,000 | 100,000,000 | |
Issuance of common stock, net of issuance costs | $ 66,913 | $ 208,276 | $ 17,501 |
Par Value (in dollars per share) | $ 0 | $ 0 | |
Shares issued (in shares) | 37,631,212 | 35,524,590 | |
ATM Equity Program | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Par Value (in dollars per share) | $ 0 | ||
Sale of Stock, Cumulative Commissions and Fees Paid | $ 1,200 | ||
Cumulative Proceeds Received on All Transactions | $ 66,400 | ||
Shares issued (in shares) | 1,646,325 | ||
nwn:AttheMarketEquityProgramEquityAvailableforIssuance | $ 43,500 | ||
ATM Equity Program | Maximum [Member] | Scenario, Plan | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Cumulative Proceeds Received on All Transactions | $ 200,000 | ||
Stock Repurchase Plan [Member] | |||
Stock Repurchase Program | |||
Stock Repurchase Program, Number of Shares Authorized to be Repurchased | 2,800,000 | ||
Stock Repurchase Program, Authorized Amount | $ 100,000 | ||
Treasury Stock, Shares, Acquired | 0 | ||
Repurchases Since Plan Inception in Year 2000 [Member] | Stock Repurchase Plan [Member] | |||
Stock Repurchase Program | |||
Treasury Stock, Shares, Acquired | 2,100,000 | ||
Treasury Stock, Value, Acquired, Cost Method | $ 83,300 | ||
Northwest Holdings [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Reserved Shares Dividend Reinvestment | 325,201 | ||
Northwest Holdings [Member] | Employee Stock Purchase Plan Member [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Common Stock, Capital Shares Reserved for Future Issuance | 306,757 |
Common Stock - Schedule of Summ
Common Stock - Schedule of Summary of Changes in Common Stock (Details) - shares | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Increase (Decrease) in Common Stock [Roll Forward] | |||
Beginning Balance | 35,524,590 | ||
Ending Balance | 37,631,212 | 35,524,590 | |
Common Stock [Member] | |||
Increase (Decrease) in Common Stock [Roll Forward] | |||
Beginning Balance | 35,525,000 | 31,129,000 | 30,589,000 |
Sales to employees under ESPP | 13,000 | 36,000 | 48,000 |
Stock-based compensation | 39,000 | 42,000 | 49,000 |
Equity issuance | 1,658,000 | 4,257,000 | 376,000 |
Stock Issued During Period, Shares, Dividend Reinvestment Plan | 69,000 | 61,000 | 67,000 |
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned | 327,000 | ||
Ending Balance | 37,631,000 | 35,525,000 | 31,129,000 |
Revenue - Disaggregation of Rev
Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | $ 1,173,227 | $ 1,039,765 | $ 828,155 |
Operating revenues | 1,197,475 | 1,037,353 | 860,400 |
Lease Income | 16,050 | 17,193 | 17,551 |
Natural Gas Distribution [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 1,109,223 | 989,654 | 783,027 |
Gas Storage Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 12,041 | 11,792 | 10,830 |
Asset Management Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 5,942 | 6,965 | 9,387 |
Appliance Center Revenue [Member] | Transferred at Point in Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 4,240 | 5,830 | 5,953 |
Other revenue [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 41,781 | 25,524 | 18,958 |
Alternative revenue [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Operating revenues | 8,198 | (19,605) | 14,694 |
Leasing revenue [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Lease Income | 16,050 | 17,193 | 17,551 |
Operating Segments [Member] | Northwest Natural Gas Company [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Operating revenues | 1,158,623 | 1,014,339 | 843,057 |
Operating Segments [Member] | Natural Gas Distribution [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Operating revenues | 1,136,400 | 989,752 | 816,887 |
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Operating revenues | 22,223 | 24,587 | 26,170 |
Corporate, Non-Segment [Member] | Northwest Holdings Other [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 38,852 | 23,014 | 17,343 |
Operating revenues | 38,852 | 23,014 | 17,343 |
Corporate, Non-Segment [Member] | Northwest Holdings Other [Member] | Natural Gas Distribution [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 |
Corporate, Non-Segment [Member] | Northwest Holdings Other [Member] | Gas Storage Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 |
Corporate, Non-Segment [Member] | Northwest Holdings Other [Member] | Asset Management Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 |
Corporate, Non-Segment [Member] | Northwest Holdings Other [Member] | Appliance Center Revenue [Member] | Transferred at Point in Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 |
Corporate, Non-Segment [Member] | Northwest Holdings Other [Member] | Other revenue [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 38,852 | 23,014 | 17,343 |
Corporate, Non-Segment [Member] | Northwest Holdings Other [Member] | Alternative revenue [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Operating revenues | 0 | 0 | 0 |
Corporate, Non-Segment [Member] | Northwest Holdings Other [Member] | Leasing revenue [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Lease Income | 0 | 0 | 0 |
Northwest Natural Gas Company [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Operating revenues | 1,158,623 | 1,014,339 | 843,057 |
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 1,134,375 | 1,016,751 | 810,812 |
Operating revenues | 1,158,623 | 1,014,339 | 843,057 |
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Natural Gas Distribution [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 1,109,223 | 989,654 | 783,027 |
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Gas Storage Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 12,041 | 11,792 | 10,830 |
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Asset Management Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 5,942 | 6,965 | 9,387 |
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Appliance Center Revenue [Member] | Transferred at Point in Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 4,240 | 5,830 | 5,953 |
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Other revenue [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 2,929 | 2,510 | 1,615 |
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Alternative revenue [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Operating revenues | 8,198 | (19,605) | 14,694 |
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Leasing revenue [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Lease Income | 16,050 | 17,193 | 17,551 |
Northwest Natural Gas Company [Member] | Operating Segments [Member] | Natural Gas Distribution [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 1,112,152 | 992,164 | 784,642 |
Operating revenues | 1,136,400 | 989,752 | 816,887 |
Northwest Natural Gas Company [Member] | Operating Segments [Member] | Natural Gas Distribution [Member] | Natural Gas Distribution [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 1,109,223 | 989,654 | 783,027 |
Northwest Natural Gas Company [Member] | Operating Segments [Member] | Natural Gas Distribution [Member] | Gas Storage Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 | 0 |
Northwest Natural Gas Company [Member] | Operating Segments [Member] | Natural Gas Distribution [Member] | Asset Management Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 | 0 |
Northwest Natural Gas Company [Member] | Operating Segments [Member] | Natural Gas Distribution [Member] | Appliance Center Revenue [Member] | Transferred at Point in Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 | 0 |
Northwest Natural Gas Company [Member] | Operating Segments [Member] | Natural Gas Distribution [Member] | Other revenue [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Including Assessed Tax | 2,929 | 2,510 | 1,615 |
Northwest Natural Gas Company [Member] | Operating Segments [Member] | Natural Gas Distribution [Member] | Alternative revenue [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Operating revenues | 8,198 | (19,605) | 14,694 |
Northwest Natural Gas Company [Member] | Operating Segments [Member] | Natural Gas Distribution [Member] | Leasing revenue [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Lease Income | 16,050 | 17,193 | 17,551 |
Northwest Natural Gas Company [Member] | Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 22,223 | 24,587 | 26,170 |
Operating revenues | 22,223 | 24,587 | 26,170 |
Northwest Natural Gas Company [Member] | Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Natural Gas Distribution [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 |
Northwest Natural Gas Company [Member] | Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Gas Storage Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 12,041 | 11,792 | 10,830 |
Northwest Natural Gas Company [Member] | Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Asset Management Revenue, Net of Regulatory Sharing [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 5,942 | 6,965 | 9,387 |
Northwest Natural Gas Company [Member] | Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Appliance Center Revenue [Member] | Transferred at Point in Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 4,240 | 5,830 | 5,953 |
Northwest Natural Gas Company [Member] | Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Other revenue [Member] | Transferred over Time [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 |
Northwest Natural Gas Company [Member] | Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Alternative revenue [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Operating revenues | 0 | 0 | 0 |
Northwest Natural Gas Company [Member] | Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Leasing revenue [Member] | |||
Disaggregation of Revenue [Line Items] | |||
Lease Income | $ 0 | $ 0 | $ 0 |
Revenue - Revenue, Remaining Pe
Revenue - Revenue, Remaining Performance Obligation (Details) $ in Thousands | Dec. 31, 2023 USD ($) performanceObligations |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Lessor, Sales-type Lease, Term of Contract | 30 years |
Lessor, Sales-type Lease, Renewal Term | 50 years |
Revenue, Remaining Performance Obligation, Amount | $ 78,100 |
Revenue, Over Time Performance Obligation, Number | performanceObligations | 1 |
Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Contract with Customer, Refund Liability | $ 0 |
Northwest Holdings Other [Member] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Contract with Customer, Refund Liability | 0 |
Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Contract with Customer, Refund Liability | 0 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 19,900 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 19,000 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 14,900 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 7,400 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 16,900 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 0 years |
Leases - Lease Revenue (Details
Leases - Lease Revenue (Details) - USD ($) | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Lessor, Lease, Description [Line Items] | |||
Lessor, Sales-type Lease, Term of Contract | 30 years | ||
Lessor, Sales-type Lease, Renewal Term | 50 years | ||
Residual Value of Leased Asset | $ 5,500,000 | $ 5,100,000 | |
Lease Revenue [Abstract] | |||
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration] | Operating revenues | Operating revenues | Operating revenues |
Sales-Type Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration] | Operating revenues | Operating revenues | Operating revenues |
Lease Income | $ 16,050,000 | $ 17,193,000 | $ 17,551,000 |
Operating Leases Payment to be Received [Abstract] | |||
Lessor, Operating Lease, Payments to be Received, Next Twelve Months | 655,000 | ||
Lessor, Operating Lease, Payments to be Received, Two Years | 652,000 | ||
Lessor, Operating Lease, Payments to be Received, Three Years | 92,000 | ||
Lessor, Operating Lease, Payments to be Received, Four Years | 79,000 | ||
Lessor, Operating Lease, Payments to be Received, Five Years | 58,000 | ||
Lessor, Operating Lease, Payments to be Received, Thereafter | 800,000 | ||
Lessor, Operating Lease, Payments to be Received | 2,336,000 | ||
Total Lease Payments to be Received [Abstract] | |||
Lease Payments to be Received, Next twelve months | 16,522,000 | ||
Lease Payments to be Received, Two Years | 15,958,000 | ||
Lease Payments to be Received, Three Years | 14,993,000 | ||
Lease Payments to be Received, Four Years | 14,600,000 | ||
Lease Payments to be Received, Five Years | 14,041,000 | ||
Lease Payments to be Received, Thereafter | 209,116,000 | ||
Lease Payments to be Received | 285,230,000 | ||
Northwest Natural Gas Company [Member] | |||
Operating Leases Payment to be Received [Abstract] | |||
Lessor, Operating Lease, Payments to be Received, Next Twelve Months | 603,000 | ||
Lessor, Operating Lease, Payments to be Received, Two Years | 599,000 | ||
Lessor, Operating Lease, Payments to be Received, Three Years | 36,000 | ||
Lessor, Operating Lease, Payments to be Received, Four Years | 22,000 | ||
Lessor, Operating Lease, Payments to be Received, Five Years | 0 | ||
Lessor, Operating Lease, Payments to be Received, Thereafter | 0 | ||
Lessor, Operating Lease, Payments to be Received | 1,260,000 | ||
Total Lease Payments to be Received [Abstract] | |||
Lease Payments to be Received, Next twelve months | 16,470,000 | ||
Lease Payments to be Received, Two Years | 15,905,000 | ||
Lease Payments to be Received, Three Years | 14,937,000 | ||
Lease Payments to be Received, Four Years | 14,543,000 | ||
Lease Payments to be Received, Five Years | 13,983,000 | ||
Lease Payments to be Received, Thereafter | 208,316,000 | ||
Lease Payments to be Received | 284,154,000 | ||
Northwest Holdings Other [Member] | |||
Operating Leases Payment to be Received [Abstract] | |||
Lessor, Operating Lease, Payments to be Received, Next Twelve Months | 52,000 | ||
Lessor, Operating Lease, Payments to be Received, Two Years | 53,000 | ||
Lessor, Operating Lease, Payments to be Received, Three Years | 56,000 | ||
Lessor, Operating Lease, Payments to be Received, Four Years | 57,000 | ||
Lessor, Operating Lease, Payments to be Received, Five Years | 58,000 | ||
Lessor, Operating Lease, Payments to be Received, Thereafter | 800,000 | ||
Lessor, Operating Lease, Payments to be Received | 1,076,000 | ||
Total Lease Payments to be Received [Abstract] | |||
Lease Payments to be Received, Next twelve months | 52,000 | ||
Lease Payments to be Received, Two Years | 53,000 | ||
Lease Payments to be Received, Three Years | 56,000 | ||
Lease Payments to be Received, Four Years | 57,000 | ||
Lease Payments to be Received, Five Years | 58,000 | ||
Lease Payments to be Received, Thereafter | 800,000 | ||
Lease Payments to be Received | 1,076,000 | ||
Sales-type Lease [Member] | |||
Sales-type Leases Payments to be Received [Abstract] | |||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Next Twelve Months | 15,867,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Two Years | 15,306,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Three Years | 14,901,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Four Years | 14,521,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Five Years | 13,983,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Thereafter | 208,316,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received | 282,894,000 | ||
Receivable with Imputed Interest, Discount | 153,806,000 | ||
Receivable with Imputed Interest, Net Amount | 129,088,000 | ||
Sales-type Lease [Member] | Northwest Natural Gas Company [Member] | |||
Sales-type Leases Payments to be Received [Abstract] | |||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Next Twelve Months | 15,867,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Two Years | 15,306,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Three Years | 14,901,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Four Years | 14,521,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Five Years | 13,983,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Thereafter | 208,316,000 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received | 282,894,000 | ||
Receivable with Imputed Interest, Discount | 153,806,000 | ||
Receivable with Imputed Interest, Net Amount | 129,088,000 | ||
Sales-type Lease [Member] | Northwest Holdings Other [Member] | |||
Sales-type Leases Payments to be Received [Abstract] | |||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Next Twelve Months | 0 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Two Years | 0 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Three Years | 0 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Four Years | 0 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Five Years | 0 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Thereafter | 0 | ||
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received | 0 | ||
North Mist Lease [Member] | |||
Lessor, Lease, Description [Line Items] | |||
Variable Lease, Payment | 0 | ||
Residual Value of Leased Asset | $ 0 | ||
Compressed Natural Gas Lease [Member] | |||
Lessor, Lease, Description [Line Items] | |||
Lessor, Sales-type Lease, Term of Contract | 10 years | ||
Other Nonoperating Income (Expense) [Member] | |||
Lease Revenue [Abstract] | |||
Lease Income | $ 600,000 | $ 600,000 | $ 500,000 |
Leases - Lease Expense (Details
Leases - Lease Expense (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Lessee, Lease, Description [Line Items] | |||
Short-term Lease, Cost | $ 925 | $ 880 | $ 1,220 |
Lessor, Operating Lease, Payments to be Received, Two Years | $ 652 | ||
Operating Lease, Weighted Average Remaining Lease Term | 16 years 2 months 12 days | 17 years 2 months 12 days | |
Lessee, Operating Lease, Liability, Payments, Due | $ 139,367 | ||
Regulatory Assets, Noncurrent | 333,443 | $ 340,432 | |
Operating Lease, Expense | $ 7,420 | 7,034 | 6,917 |
New Headquarters Lease [Member] | |||
Lessee, Lease, Description [Line Items] | |||
Lessee, Operating Lease, Term of Contract | 20 years | ||
Regulatory Assets, Noncurrent | $ 8,000 | 6,900 | |
Lessee, Operating Lease, Term of Contract | 20 years | ||
New Headquarters Lease [Member] | New Headquarters Lease Renewal Term 1 of 2 [Member] | |||
Lessee, Lease, Description [Line Items] | |||
Lessee, Operating Lease, Term of Contract | 7 years | ||
Lessee, Operating Lease, Term of Contract | 7 years | ||
New Headquarters Lease [Member] | New Headquarters Lease 1st Renewal Period [Member] | |||
Lessee, Lease, Description [Line Items] | |||
Lessee, Operating Lease, Term of Contract | 7 years | ||
Lessee, Operating Lease, Term of Contract | 7 years | ||
Short Term Leases | |||
Lessee, Lease, Description [Line Items] | |||
Lessee, Operating Lease, Term of Contract | 12 months | ||
Lessee, Operating Lease, Term of Contract | 12 months | ||
Minimum [Member] | |||
Lessee, Lease, Description [Line Items] | |||
Lessee, Operating Lease, Term of Contract | 9 months | ||
Lessee, Operating Lease, Term of Contract | 9 months | ||
Maximum [Member] | |||
Lessee, Lease, Description [Line Items] | |||
Lessee, Operating Lease, Term of Contract | 16 years | ||
Lessee, Operating Lease, Term of Contract | 16 years | ||
Northwest Natural Gas Company [Member] | |||
Lessee, Lease, Description [Line Items] | |||
Short-term Lease, Cost | $ 925 | $ 880 | 1,220 |
Lessor, Operating Lease, Payments to be Received, Two Years | $ 599 | ||
Operating Lease, Weighted Average Discount Rate, Percent | 7.30% | 7.30% | |
Lessee, Operating Lease, Liability, Payments, Due | $ 138,736 | ||
Regulatory Assets, Noncurrent | 333,418 | $ 340,407 | |
Operating Lease, Expense | 7,244 | 7,003 | 6,859 |
Northwest Holdings Other [Member] | Corporate, Non-Segment [Member] | |||
Lessee, Lease, Description [Line Items] | |||
Short-term Lease, Cost | 0 | 0 | 0 |
Lessee, Operating Lease, Liability, Payments, Due | 631 | ||
Operating Lease, Expense | $ 176 | $ 31 | $ 58 |
Leases - Lease Asset and Liabil
Leases - Lease Asset and Liabilities (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Operating Lease Asset and Liabilities [Abstract] | |||
Operating Lease, Right-of-Use Asset | $ 71,308 | $ 73,429 | |
Operating Lease, Liability, Current | 2,333 | 1,514 | |
Operating Lease, Liability, Noncurrent | 77,167 | 78,965 | |
Operating Lease, Liability | $ 79,500 | $ 80,479 | |
Operating Lease, Weighted Average Remaining Lease Term | 16 years 2 months 12 days | 17 years 2 months 12 days | |
Maturity of Operating Lease Liabilities [Abstract] | |||
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months | $ 7,667 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Two | 7,538 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Three | 7,514 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Four | 7,645 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Five | 7,725 | ||
Lessee, Operating Lease, Liability, Payments, Due after Year Five | 101,278 | ||
Lessee, Operating Lease, Liability, Payments, Due | 139,367 | ||
Lessee, Operating Lease, Liability, Undiscounted Excess Amount | 59,867 | ||
Operating Lease, Liability | 79,500 | $ 80,479 | |
Operating Lease, Liability, Current | 2,333 | 1,514 | |
Operating Lease, Liability, Noncurrent | 77,167 | 78,965 | |
Lease Not Yet Commenced [Abstract] | |||
Lessee, Operating Lease, Liability, Payments, Due | 139,367 | ||
Leases Cash Flow [Abstract] | |||
Operating Lease, Payments | 7,610 | 7,057 | $ 6,898 |
Finance Lease, Principal Payments | 369 | 524 | 801 |
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability | 659 | 977 | 223 |
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability | $ 470 | $ 270 | 314 |
Finance Leases [Abstract] | |||
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] | Total property, plant, and equipment, net | Total property, plant, and equipment, net | |
Prior Period Disclosures [Abstract] | |||
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months | $ 7,667 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Two | 7,538 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Three | 7,514 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Four | 7,645 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Five | 7,725 | ||
Lessee, Operating Lease, Liability, Payments, Due after Year Five | 101,278 | ||
Lessee, Operating Lease, Liability, Payments, Due | 139,367 | ||
Regulatory Assets, Noncurrent | 333,443 | $ 340,432 | |
Finance Lease, Liability, to be Paid | 0 | ||
Northwest Natural Gas Company [Member] | |||
Operating Lease Asset and Liabilities [Abstract] | |||
Operating Lease, Right-of-Use Asset | 70,728 | 72,720 | |
Operating Lease, Liability, Current | 2,128 | 1,363 | |
Operating Lease, Liability, Noncurrent | 76,757 | 78,345 | |
Operating Lease, Liability | $ 78,885 | $ 79,708 | |
Operating Lease, Weighted Average Discount Rate, Percent | 7.30% | 7.30% | |
Maturity of Operating Lease Liabilities [Abstract] | |||
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months | $ 7,484 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Two | 7,362 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Three | 7,361 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Four | 7,538 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Five | 7,719 | ||
Lessee, Operating Lease, Liability, Payments, Due after Year Five | 101,272 | ||
Lessee, Operating Lease, Liability, Payments, Due | 138,736 | ||
Lessee, Operating Lease, Liability, Undiscounted Excess Amount | 59,851 | ||
Operating Lease, Liability | 78,885 | $ 79,708 | |
Operating Lease, Liability, Current | 2,128 | 1,363 | |
Operating Lease, Liability, Noncurrent | 76,757 | 78,345 | |
Lease Not Yet Commenced [Abstract] | |||
Lessee, Operating Lease, Liability, Payments, Due | 138,736 | ||
Leases Cash Flow [Abstract] | |||
Operating Lease, Payments | 7,434 | 6,993 | 6,840 |
Finance Lease, Principal Payments | 369 | 524 | 801 |
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability | 659 | 309 | 223 |
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability | 369 | 270 | 314 |
Prior Period Disclosures [Abstract] | |||
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months | 7,484 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Two | 7,362 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Three | 7,361 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Four | 7,538 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Five | 7,719 | ||
Lessee, Operating Lease, Liability, Payments, Due after Year Five | 101,272 | ||
Lessee, Operating Lease, Liability, Payments, Due | 138,736 | ||
Regulatory Assets, Noncurrent | 333,418 | 340,407 | |
Corporate, Non-Segment [Member] | Northwest Holdings Other [Member] | |||
Operating Lease Asset and Liabilities [Abstract] | |||
Operating Lease, Right-of-Use Asset | 580 | 709 | |
Operating Lease, Liability, Current | 205 | 151 | |
Operating Lease, Liability, Noncurrent | 410 | 620 | |
Operating Lease, Liability | 615 | 771 | |
Maturity of Operating Lease Liabilities [Abstract] | |||
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months | 183 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Two | 176 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Three | 153 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Four | 107 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Five | 6 | ||
Lessee, Operating Lease, Liability, Payments, Due after Year Five | 6 | ||
Lessee, Operating Lease, Liability, Payments, Due | 631 | ||
Lessee, Operating Lease, Liability, Undiscounted Excess Amount | 16 | ||
Operating Lease, Liability | 615 | 771 | |
Operating Lease, Liability, Current | 205 | 151 | |
Operating Lease, Liability, Noncurrent | 410 | 620 | |
Lease Not Yet Commenced [Abstract] | |||
Lessee, Operating Lease, Liability, Payments, Due | 631 | ||
Leases Cash Flow [Abstract] | |||
Operating Lease, Payments | 176 | 64 | 58 |
Finance Lease, Principal Payments | 0 | 0 | 0 |
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability | 0 | 668 | 0 |
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability | 101 | $ 0 | $ 0 |
Prior Period Disclosures [Abstract] | |||
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months | 183 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Two | 176 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Three | 153 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Four | 107 | ||
Lessee, Operating Lease, Liability, Payments, Due Year Five | 6 | ||
Lessee, Operating Lease, Liability, Payments, Due after Year Five | 6 | ||
Lessee, Operating Lease, Liability, Payments, Due | $ 631 | ||
Maximum [Member] | |||
Prior Period Disclosures [Abstract] | |||
Lessee, Operating Lease, Term of Contract | 16 years |
Stock-Based Compensation - Long
Stock-Based Compensation - Long Term Incentive Plan (Details) - USD ($) | 12 Months Ended | 36 Months Ended | ||||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
Restricted Stock Units [Abstract] | ||||||
Return on Invested Capital Threshold, Performance Shares | 3 years | |||||
Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized | 1,100,000 | |||||
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant, Any Award Type | 180,755 | |||||
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 0 | 0 | ||||
Restricted Stock Units (RSUs) [Member] | Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 97,291 | 99,848 | 87,727 | 87,727 | 82,464 | |
Performance Shares [Abstract] | ||||||
Share-based Payment Arrangement, Expense | $ 1,900,000 | $ 2,100,000 | $ 2,000,000 | |||
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $ 3,100,000 | |||||
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ 49.80 | $ 50.44 | $ 54.87 | $ 54.87 | $ 59.40 | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value | $ 56.65 | $ 55.90 | $ 60.06 | |||
Restricted Stock Units [Abstract] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | 4 years | |||||
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | (36,393) | (33,054) | (31,733) | |||
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 45,532 | 48,212 | 38,160 | |||
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ 48.24 | $ 46.50 | $ 49.16 | |||
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period | (11,696) | (3,037) | (1,164) | |||
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | $ 49.98 | $ 56.34 | $ 46.82 | |||
Performance Shares [Member] | Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share Based Compensation Award Target Share | 48,030 | |||||
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | 0 | |||||
Performance Shares [Abstract] | ||||||
Share-based Payment Arrangement, Expense | $ 1,581,000 | |||||
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $ 0 | |||||
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ 49.17 | |||||
Performance Shares [Member] | A 2021 Award | Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share Based Compensation Award Target Share | 48,030 | |||||
Performance Shares [Abstract] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted | 40,719 | |||||
Share-based Payment Arrangement, Expense | $ 1,581,000 | $ 1,581,000 | ||||
Performance Shares [Member] | A 2020 Award | Long Term Incentive Plan [Member] | ||||||
Performance Shares [Abstract] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted | 29,472 | |||||
Share-based Payment Arrangement, Expense | $ 888,000 | $ 888,000 | ||||
Performance Shares [Member] | A 2019 Award [Member] | Long Term Incentive Plan [Member] | ||||||
Performance Shares [Abstract] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted | 37,430 | |||||
Share-based Payment Arrangement, Expense | $ 1,323,000 | $ 1,323,000 | ||||
Performance Shares [Member] | A 2022 Award | Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share Based Compensation Award Target Share | 0 | |||||
Performance Shares [Abstract] | ||||||
Share-based Payment Arrangement, Expense | $ 0 | |||||
Performance Shares [Member] | A 2023 Award | Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share Based Compensation Award Target Share | 0 | |||||
Performance Shares [Abstract] | ||||||
Share-based Payment Arrangement, Expense | $ 0 | |||||
Maximum [Member] | Performance Shares [Member] | Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share Based Compensation Award Target Share | 96,060 | |||||
Maximum [Member] | Performance Shares [Member] | A 2021 Award | Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share Based Compensation Award Target Share | 96,060 | |||||
Maximum [Member] | Performance Shares [Member] | A 2022 Award | Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share Based Compensation Award Target Share | 0 | |||||
Maximum [Member] | Performance Shares [Member] | A 2023 Award | Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share Based Compensation Award Target Share | 0 | |||||
Target Achieved [Member] | Performance Shares [Member] | A 2022 Award | Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share Based Compensation Award Target Share | 49,100 | |||||
Target Achieved [Member] | Performance Shares [Member] | A 2023 Award | Long Term Incentive Plan [Member] | ||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||
Share Based Compensation Award Target Share | 52,765 |
Stock-Based Compensation - Rest
Stock-Based Compensation - Restated Stock Option Plan (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Share-based Payment Arrangement, Expense, Tax Benefit | $ 872 | $ 762 | $ 866 |
Stock-Based Compensation - Empl
Stock-Based Compensation - Employee Stock Purchase Plan (Details) - Employee Stock Purchase Plan [Member] | 12 Months Ended |
Dec. 31, 2023 USD ($) | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent | 85% |
Maximum Value Of Stock Employees Are Allowed To Purchase | $ 21,224 |
Stock-Based Compensation - Stoc
Stock-Based Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Share-based Payment Arrangement, Expense, Tax Benefit | $ (872) | $ (762) | $ (866) |
Share-based Payment Arrangement, Expense, after Tax | 2,421 | 2,115 | 2,406 |
Share-based Payment Arrangement, Amount Capitalized | 305 | 351 | 344 |
Operations and Maintenance Expense [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Share-based Payment Arrangement, Expense | $ 3,293 | $ 2,877 | $ 3,272 |
Debt (Details)
Debt (Details) | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||||
Mar. 31, 2024 | Sep. 30, 2023 | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) numberOfProjects | Dec. 31, 2022 USD ($) | Jan. 31, 2024 USD ($) | Aug. 04, 2023 USD ($) | Feb. 23, 2023 USD ($) | |
Maturities of Long-term Debt [Abstract] | ||||||||
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months | $ 150,868,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Two | 30,824,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Three | 110,852,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Four | 65,581,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Five | 10,866,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal after Year Five | 1,217,353,000 | |||||||
Debt Instruments [Abstract] | ||||||||
Long-Term Debt, Current Maturities, Gross | 150,900,000 | $ 90,700,000 | ||||||
Liabilities, Fair Value Disclosure [Abstract] | ||||||||
Long-term Debt | 1,576,300,000 | 1,336,864,000 | ||||||
Other Long-Term Debt | 6,600,000 | 6,200,000 | ||||||
Unamortized Debt Issuance Expense | 10,044,000 | 8,987,000 | ||||||
Debt Instrument, Fair Value Disclosure | 1,447,941,000 | 1,148,395,000 | ||||||
Long-term Debt, Gross | $ 1,586,344,000 | 1,345,851,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Commercial Paper, Maximum Maturity | 5 days | |||||||
Commercial Paper, Average Maturity | 4 days | |||||||
Long-term debt | $ 1,425,435,000 | 1,246,167,000 | ||||||
Short-term debt | $ 89,780,000 | 258,200,000 | ||||||
Investments, Number of RNG Development Projects | numberOfProjects | 4 | |||||||
NWN Water Term Loan Due 2026 | ||||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Derivative, Fixed Interest Rate | 3.80% | |||||||
18 Month Credit Agreement Due March 15, 2024 | ||||||||
Credit Agreements [Abstract] | ||||||||
Debt Instrument Covenant Consolidated Indebtedness To Capitalization Ratio | 70% | |||||||
Debt Outstanding | ||||||||
Proceeds from Issuance of Debt | $ 100,000,000 | $ 100,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Long-Term Debt, Weighted Average Interest Rate, at Point in Time | 5.50% | 4.20% | ||||||
Derivative, Fixed Interest Rate | 4.70% | |||||||
18 Month Credit Agreement Due March 15, 2024 | Forecast [Member] | ||||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Short-Term Debt, Refinanced, Amount | $ 150,000,000 | |||||||
Note 5180 Series due 2034 | ||||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.18% | |||||||
Note 5230 Series due 2038 | ||||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.23% | |||||||
Line of Credit [Member] | ||||||||
Credit Agreements [Abstract] | ||||||||
Line of Credit Facility, Amount Outstanding | $ 73,000,000 | $ 88,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Short-term Debt, Weighted Average Interest Rate, at Point in Time | 6.40% | 5.30% | ||||||
Short-term Debt, Weighted Average Interest Rate, at Point in Time | 6.40% | 5.30% | ||||||
.0578 Series due 2028 | ||||||||
Repayments of Long-term Debt [Abstract] | ||||||||
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed | 100% | |||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.78% | |||||||
Debt Instrument, Unused Borrowing Capacity, Amount | $ 100,000,000 | |||||||
.0578 Series due 2028 | Minimum [Member] | ||||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Redemption Price, Percentage | 5% | |||||||
0584 Series due 2028 | ||||||||
Repayments of Long-term Debt [Abstract] | ||||||||
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed | 100% | |||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.84% | |||||||
Debt Instrument, Unused Borrowing Capacity, Amount | $ 50,000,000 | |||||||
0584 Series due 2028 | Minimum [Member] | ||||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Redemption Price, Percentage | 5% | |||||||
Northwest Natural Gas Company [Member] | ||||||||
Maturities of Long-term Debt [Abstract] | ||||||||
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months | $ 0 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Two | 30,000,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Three | 55,000,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Four | 64,700,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Five | 10,000,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal after Year Five | 1,215,000,000 | |||||||
Debt Instruments [Abstract] | ||||||||
Long-Term Debt, Current Maturities, Gross | 0 | $ 90,000,000 | ||||||
Long-term Debt, Excluding Current Maturities, Gross | 1,374,700,000 | 1,044,700,000 | ||||||
Liabilities, Fair Value Disclosure [Abstract] | ||||||||
Long-term Debt | 1,364,732,000 | 1,125,877,000 | ||||||
Unamortized Debt Issuance Expense | 9,968,000 | 8,823,000 | ||||||
Debt Instrument, Fair Value Disclosure | 1,236,559,000 | 944,383,000 | ||||||
Long-term Debt, Gross | $ 1,374,700,000 | $ 1,134,700,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Long-Term Debt, Weighted Average Interest Rate, at Point in Time | 4.70% | 4.50% | ||||||
Long-term debt | $ 1,364,732,000 | $ 1,035,935,000 | ||||||
Short-term debt | 16,780,000 | 170,200,000 | ||||||
Northwest Natural Gas Company [Member] | Note 3600 Series Due 2050 | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 150,000,000 | $ 150,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 3.60% | 3.60% | ||||||
Northwest Natural Gas Company [Member] | Note 3869 Series Due 2049 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 90,000,000 | $ 90,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 3.869% | 3.869% | ||||||
Northwest Natural Gas Company [Member] | Note 4110 Series Due 2048 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 50,000,000 | $ 50,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 4.11% | 4.11% | ||||||
Northwest Natural Gas Company [Member] | Note 3685 Series Due 2047 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 75,000,000 | $ 75,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 3.685% | 3.685% | ||||||
Northwest Natural Gas Company [Member] | Note 4136 Series Due 2046 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 40,000,000 | $ 40,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 4.136% | 4.136% | ||||||
Northwest Natural Gas Company [Member] | Note 4000 Series Due 2042 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 50,000,000 | $ 50,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 4% | 4% | ||||||
Northwest Natural Gas Company [Member] | Note 5250 Series Due 2035 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 10,000,000 | $ 10,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.25% | 5.25% | ||||||
Northwest Natural Gas Company [Member] | Note 5660 Series Due 2033 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 40,000,000 | $ 40,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.66% | 5.66% | ||||||
Northwest Natural Gas Company [Member] | Note 5820 Series Due 2032 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 30,000,000 | $ 30,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.82% | 5.82% | ||||||
Northwest Natural Gas Company [Member] | Note 7850 Series Due 2030 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 10,000,000 | $ 10,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 7.85% | 7.85% | ||||||
Northwest Natural Gas Company [Member] | Note 7740 Series Due 2030 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 20,000,000 | $ 20,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 7.74% | 7.74% | ||||||
Northwest Natural Gas Company [Member] | Note 3141 Series Due 2029 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 50,000,000 | $ 50,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 3.141% | 3.141% | ||||||
Northwest Natural Gas Company [Member] | Note 6650 Series Due 2028 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 10,000,000 | $ 10,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 6.65% | 6.65% | ||||||
Northwest Natural Gas Company [Member] | Note 6650 Series Due 2027 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 19,700,000 | $ 19,700,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 6.65% | 6.65% | ||||||
Northwest Natural Gas Company [Member] | Note 2822 Series Due 2027 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 25,000,000 | $ 25,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 2.822% | 2.822% | ||||||
Northwest Natural Gas Company [Member] | Note 7000 Series Due 2027 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 20,000,000 | $ 20,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 7% | 7% | ||||||
Northwest Natural Gas Company [Member] | Note 3211 Series Due 2026 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 35,000,000 | $ 35,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 3.211% | 3.211% | ||||||
Northwest Natural Gas Company [Member] | Note 7050 Series Due 2026 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 20,000,000 | $ 20,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 7.05% | 7.05% | ||||||
Northwest Natural Gas Company [Member] | Note 6520 Series Due 2025 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 10,000,000 | $ 10,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 6.52% | 6.52% | ||||||
Northwest Natural Gas Company [Member] | Note 7720 Series Due 2025 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 20,000,000 | $ 20,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 7.72% | 7.72% | ||||||
Northwest Natural Gas Company [Member] | Note 5620 Series Due 2023 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 0 | $ 40,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.62% | 5.62% | ||||||
Northwest Natural Gas Company [Member] | Note 3542 Series Due 2023 [Member] | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 0 | $ 50,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 3.542% | 3.542% | ||||||
Northwest Natural Gas Company [Member] | Note 4780 Series due 2052 | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 140,000,000 | $ 140,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 4.78% | 4.78% | ||||||
Northwest Natural Gas Company [Member] | Note 3078 Series due 2051 | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 130,000,000 | $ 130,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 3.078% | 3.078% | ||||||
Northwest Natural Gas Company [Member] | Note 5180 Series due 2034 | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 80,000,000 | $ 0 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.18% | 5.18% | ||||||
Proceeds from Issuance of First Mortgage Bond | $ 80,000,000 | |||||||
Northwest Natural Gas Company [Member] | Note 5230 Series due 2038 | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 50,000,000 | $ 0 | $ 50,000,000 | |||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.23% | 5.23% | ||||||
Northwest Natural Gas Company [Member] | Note 5750 Series due 2033 | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 100,000,000 | $ 0 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.75% | 5.75% | ||||||
Proceeds from Issuance of Medium-term Notes | $ 100,000,000 | |||||||
Northwest Natural Gas Company [Member] | Note 5430 Series due 2053 | ||||||||
Debt Instruments [Abstract] | ||||||||
Secured Debt | $ 100,000,000 | $ 0 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.43% | 5.43% | ||||||
Proceeds from Issuance of First Mortgage Bond | $ 100,000,000 | |||||||
Northwest Natural Gas Company [Member] | Commercial Paper | ||||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Short-term Debt, Weighted Average Interest Rate, at Point in Time | 5.50% | 4.60% | ||||||
Short-term Debt, Weighted Average Interest Rate, at Point in Time | 5.50% | 4.60% | ||||||
Short-term debt | $ 16,800,000 | $ 170,200,000 | ||||||
NWN Water | NWN Water Term Loan Due 2026 | ||||||||
Liabilities, Fair Value Disclosure [Abstract] | ||||||||
Long-term Debt | $ 55,000,000 | $ 55,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Long-Term Debt, Weighted Average Interest Rate, at Point in Time | 4.70% | 2.50% | ||||||
NWN Water | 18 Month Credit Agreement Due March 15, 2024 | ||||||||
Debt Outstanding | ||||||||
Proceeds from Issuance of Debt | $ 50,000,000 | $ 50,000,000 | ||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Long-Term Debt, Weighted Average Interest Rate, at Point in Time | 5.80% | 4.20% | ||||||
Northwest Holdings Other [Member] | ||||||||
Maturities of Long-term Debt [Abstract] | ||||||||
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months | $ 150,868,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Two | 824,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Three | 55,852,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Four | 881,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal in Year Five | 866,000 | |||||||
Long-term Debt, Maturities, Repayments of Principal after Year Five | 2,353,000 | |||||||
Liabilities, Fair Value Disclosure [Abstract] | ||||||||
Long-term Debt, Gross | 211,644,000 | |||||||
Northwest Holdings Other [Member] | Corporate, Non-Segment [Member] | NWN Water Term Loan Due 2026 | ||||||||
Liabilities, Fair Value Disclosure [Abstract] | ||||||||
Long-term Debt | 55,000,000 | |||||||
Line of Credit [Member] | ||||||||
Credit Agreements [Abstract] | ||||||||
Line of Credit Facility, Maximum Borrowing Capacity | 200,000,000 | |||||||
Line of Credit Facility Contingent Increase To Maximum Borrowing Capacity | $ 300,000,000 | |||||||
Debt Instrument Covenant Consolidated Indebtedness To Capitalization Ratio | 70% | |||||||
Line of Credit [Member] | First Available Extension Period | ||||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Line of Credit Facility, Expiration Period | 1 year | |||||||
Line of Credit [Member] | Second Available Extension Period | ||||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Line of Credit Facility, Expiration Period | 1 year | |||||||
Line of Credit [Member] | Northwest Natural Gas Company [Member] | ||||||||
Credit Agreements [Abstract] | ||||||||
Line of Credit Facility, Maximum Borrowing Capacity | $ 400,000,000 | |||||||
Line of Credit Facility Contingent Increase To Maximum Borrowing Capacity | $ 600,000,000 | |||||||
Line of Credit [Member] | Northwest Natural Gas Company [Member] | First Available Extension Period | ||||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Line of Credit Facility, Expiration Period | 1 year | |||||||
Line of Credit [Member] | Northwest Natural Gas Company [Member] | Second Available Extension Period | ||||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Line of Credit Facility, Expiration Period | 1 year | |||||||
Letter of Credit [Member] | ||||||||
Credit Agreements [Abstract] | ||||||||
Line of Credit Facility, Maximum Borrowing Capacity | $ 40,000,000 | |||||||
Letters of Credit Outstanding, Amount | 0 | |||||||
Letter of Credit [Member] | Northwest Natural Gas Company [Member] | ||||||||
Credit Agreements [Abstract] | ||||||||
Line of Credit Facility, Maximum Borrowing Capacity | 60,000,000 | |||||||
Letters of Credit Outstanding, Amount | $ 1 | $ 0 | $ 15,000,000 | |||||
Letter of Credit [Member] | Northwest Natural Gas Company [Member] | Subsequent Event [Member] | ||||||||
Credit Agreements [Abstract] | ||||||||
Line of Credit Facility, Maximum Borrowing Capacity | $ 100,000,000 | |||||||
Short-term Debt, Other Disclosures [Abstract] | ||||||||
Debt Instrument, Restrictive Covenants | 70 |
Pension and Other Postretirem_3
Pension and Other Postretirement Benefits Costs - Changes in Benefit Obligations and Fair Value of Plan Assets (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Pension Plan [Member] | |||
Reconciliation of change in plan assets: | |||
Fair value of plan assets at January 1 | $ 280,306 | ||
Fair value of plan assets at December 31 | 283,443 | $ 280,306 | |
Qualified Pension Plans, Defined Benefit [Member] | |||
Reconciliation of change in plan assets: | |||
Defined Benefit Plan, Accumulated Benefit Obligation | 363,500 | 353,400 | |
Northwest Natural Gas Company [Member] | Other Postretirement Benefits Plan [Member] | |||
Reconciliation of change in benefit obligation: | |||
Obligation at January 1 | 19,880 | 27,223 | |
Service cost | 105 | 193 | |
Interest cost | 1,067 | 724 | |
Net actuarial gain (loss) | 2,208 | 6,234 | |
Defined Benefit Plan, Benefit Obligation, Benefits Paid | (1,793) | (2,026) | |
Benefits paid | (1,793) | (2,026) | $ (2,050) |
Obligation at December 31 | 21,467 | 19,880 | 27,223 |
Reconciliation of change in plan assets: | |||
Fair value of plan assets at January 1 | 0 | 0 | |
Actual return on plan assets | 0 | 0 | |
Employer contributions | 1,793 | 2,026 | |
Benefits paid | (1,793) | (2,026) | (2,050) |
Fair value of plan assets at December 31 | 0 | 0 | 0 |
Northwest Natural Gas Company [Member] | Pension Plan [Member] | |||
Reconciliation of change in benefit obligation: | |||
Obligation at January 1 | 413,413 | 542,618 | |
Service cost | 3,922 | 5,933 | |
Interest cost | 21,019 | 14,593 | |
Net actuarial gain (loss) | 15,066 | 122,168 | |
Defined Benefit Plan, Benefit Obligation, Benefits Paid | (27,970) | (27,563) | |
Benefits paid | (27,970) | (27,563) | (25,371) |
Obligation at December 31 | 425,450 | 413,413 | 542,618 |
Reconciliation of change in plan assets: | |||
Fair value of plan assets at January 1 | 280,304 | 399,217 | |
Actual return on plan assets | 28,841 | (93,703) | |
Employer contributions | 2,269 | 2,353 | |
Benefits paid | (27,970) | (27,563) | (25,371) |
Fair value of plan assets at December 31 | 283,444 | 280,304 | $ 399,217 |
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease) | (11,000) | ||
Defined Benefit Plan, Plan Assets, Period Increase (Decrease) | 3,100 | ||
Liability, Defined Benefit Pension Plan | 7,900 | ||
Northwest Natural Gas Company [Member] | Non-qualified Benefit Plans | |||
Reconciliation of change in plan assets: | |||
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease) | (1,000) | ||
Northwest Natural Gas Company [Member] | Qualified Pension Plans, Defined Benefit [Member] | |||
Reconciliation of change in benefit obligation: | |||
Obligation at January 1 | 381,600 | ||
Obligation at December 31 | 392,600 | 381,600 | |
Reconciliation of change in plan assets: | |||
Fair value of plan assets at January 1 | 280,300 | ||
Fair value of plan assets at December 31 | 283,400 | 280,300 | |
Defined Benefit Plan, Funded (Unfunded) Status of Plan | (109,200) | ||
Northwest Holdings and Northwest Natural [Member] | Other Postretirement Benefits Plan [Member] | |||
Reconciliation of change in plan assets: | |||
Defined Benefit Plan, Funded (Unfunded) Status of Plan | (21,467) | (19,880) | |
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease) | (1,600) | ||
Northwest Holdings and Northwest Natural [Member] | Pension Plan [Member] | |||
Reconciliation of change in plan assets: | |||
Defined Benefit Plan, Funded (Unfunded) Status of Plan | $ (142,006) | $ (133,109) |
Pension and Other Postretirem_4
Pension and Other Postretirement Benefits Costs - Narrative (Details) - USD ($) $ in Thousands | 12 Months Ended | |||
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||||
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate | 4% | |||
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate | 2029 | |||
Payment for Pension and Other Postretirement Benefits | $ 0 | |||
Expected future employer contributions | $ 20,600 | |||
Pension Plan Withdrawal Liability, Payments | 20 years | |||
Regulatory amortization of gas reserves | $ 3,217 | $ 5,589 | $ 13,897 | |
Forecast [Member] | ||||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||||
Regulatory amortization of gas reserves | $ 5,200 | |||
Pension Plan [Member] | ||||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||||
Plan Assets, Amount | $ 283,443 | 280,306 | ||
Other Postretirement Benefits Plan [Member] | ||||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||||
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year | 6.50% | |||
Non-Qualified Pension Plans, Defined Benefit [Member] | ||||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||||
Plan Assets, Amount | $ 0 | |||
Defined Benefit Plan, Benefit Obligation | 32,800 | 31,800 | ||
Qualified Pension Plans, Defined Benefit [Member] | ||||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||||
Defined Benefit Plan, Accumulated Benefit Obligation | $ 363,500 | $ 353,400 |
Pension and Other Postretirem_5
Pension and Other Postretirement Benefits Costs - Schedule of Amounts Realized in Other Comprehensive Loss (Income) (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Pension Plan [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Regulatory Asset, Net actuarial loss (gain) | $ 10,318 | $ 2,833 | $ (32,258) |
Regulatory Asset, Prior service cost | 0 | 0 | 0 |
Regulatory Asset, Actuarial loss | 0 | (11,531) | (21,250) |
Regulatory Asset, Total | 10,318 | (8,698) | (53,508) |
Other Postretirement Benefits Plan [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Regulatory Asset, Net actuarial loss (gain) | 2,208 | (6,234) | (688) |
Regulatory Asset, Prior service cost | 0 | 333 | 468 |
Regulatory Asset, Actuarial loss | 0 | (426) | (645) |
Regulatory Asset, Total | 2,208 | (6,327) | (865) |
Qualified Pension Plans, Defined Benefit [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Amounts reclassified to AOCL | 1,630 | (5,706) | (812) |
Other Comprehensive Loss (Income), Prior service cost | 0 | 0 | 0 |
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax | (713) | (1,081) | (1,225) |
Total reclassifications before tax | $ 917 | $ (6,787) | $ (2,037) |
Pension and Other Postretirem_6
Pension and Other Postretirement Benefits Costs - Schedule of Amount Recognized in AOCL (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Qualified Pension Plans, Defined Benefit [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
AOCL, Prior Service Costs (Credit) | $ 0 | $ 0 |
AOCL, Net Actuarial Loss | 9,634 | 8,717 |
AOCL, Total | 9,634 | 8,717 |
Pension Costs [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Regulatory Assets, Prior Service Cost (Credit) | 0 | 0 |
Regulatory Assets, Net Actuarial Loss | 112,558 | 102,240 |
Regulatory Assets | 112,558 | 102,240 |
Postretirement Benefit Costs [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Regulatory Assets, Prior Service Cost (Credit) | 0 | 0 |
Regulatory Assets, Net Actuarial Loss | 1,382 | 826 |
Regulatory Assets | $ 1,382 | $ 826 |
Pension and Other Postretirem_7
Pension and Other Postretirement Benefits Costs - Schedule of AOCL and Changes in AOCL, Non-Qualified Employee Plans (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2023 | Dec. 31, 2022 | |
AOCI Attributable to Parent, Net of Tax [Roll Forward] | ||
Beginning balance | $ 6,285 | |
Ending balance | 7,049 | $ 6,285 |
Northwest Holdings and Northwest Natural [Member] | Non-Qualified Pension Plans, Defined Benefit [Member] | ||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | ||
Beginning balance | 6,414 | 11,404 |
Amounts reclassified to AOCL | (1,676) | 5,706 |
Amortization of actuarial losses | 558 | 1,081 |
Total reclassifications before tax | (1,118) | 6,787 |
Tax benefit (expense) | 295 | (1,797) |
Total reclassifications for the period | (823) | 4,990 |
Ending balance | (7,237) | 6,414 |
Northwest Natural Gas Company [Member] | ||
AOCI Attributable to Parent, Net of Tax [Roll Forward] | ||
Beginning balance | 6,414 | |
Ending balance | $ 7,237 | $ 6,414 |
Pension and Other Postretirem_8
Pension and Other Postretirement Benefits Costs - Schedule of Pension Plan Target Allocations (Details) - Northwest Natural Gas Company [Member] | Dec. 31, 2023 |
Long government/credit [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Target allocation, percentage | 20% |
U.S. large cap equity [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Target allocation, percentage | 18% |
Non-U.S. equity [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Target allocation, percentage | 18% |
Absolute Return Strategy Investment Securities [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Target allocation, percentage | 12% |
U.S. small/mid cap equity [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Target allocation, percentage | 10% |
Real estate funds [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Target allocation, percentage | 7% |
High yield bonds [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Target allocation, percentage | 5% |
Emerging markets equity [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Target allocation, percentage | 5% |
Emerging market debt [Member] | |
Defined Benefit Plan Disclosure [Line Items] | |
Target allocation, percentage | 5% |
Pension and Other Postretirem_9
Pension and Other Postretirement Benefits Costs - Schedule of Components of Net Periodic Benefit Cost for NW Natural (Details) - Northwest Natural Gas Company Consolidated [Member] - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Other Postretirement Benefits Plan [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Service cost | $ 105 | $ 193 | $ 238 |
Interest cost | 1,067 | 724 | 684 |
Expected return on plan assets | 0 | 0 | 0 |
Amortization of prior service credit | 0 | (333) | (468) |
Amortization of net actuarial loss | 0 | (426) | (645) |
Net periodic (benefit) cost | 1,172 | 1,010 | 1,099 |
Amount allocated to construction | 36 | 76 | 93 |
Net periodic (benefit) cost charged to expense | 1,136 | 934 | 1,006 |
Amortization of Regulatory Balancing Account | 0 | 0 | 0 |
Defined Benefit Plan Net Amount Charged To Expense | 1,136 | 934 | 1,006 |
Pension Plan [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Service cost | 3,922 | 5,933 | 6,981 |
Interest cost | 21,018 | 14,593 | 13,448 |
Expected return on plan assets | 25,723 | 25,698 | 24,232 |
Amortization of prior service credit | 0 | 0 | 0 |
Amortization of net actuarial loss | (713) | (12,612) | (22,475) |
Net periodic (benefit) cost | (70) | 7,440 | 18,672 |
Amount allocated to construction | 1,684 | 2,621 | 3,015 |
Net periodic (benefit) cost charged to expense | (1,754) | 4,819 | 15,657 |
Amortization of Regulatory Balancing Account | 7,131 | 7,131 | 7,131 |
Defined Benefit Plan Net Amount Charged To Expense | 5,377 | $ 11,950 | $ 22,788 |
Operating Expense [Member] | Pension Plan [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Regulatory Pension Disallowance | 2,600 | ||
Other Nonoperating Income (Expense) [Member] | Pension Plan [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Regulatory Pension Disallowance | $ 4,500 |
Pension and Other Postretire_10
Pension and Other Postretirement Benefits Costs - Schedule of Assumptions Used (Details) | 12 Months Ended | |||||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2026 | Dec. 31, 2025 | Dec. 31, 2024 | |
Other Postretirement Benefits Plan [Member] | ||||||
Assumptions for net periodic benefit cost: | ||||||
Weighted-average discount rate | 5.19% | 2.72% | 2.34% | |||
Assumptions for year-end funded status: | ||||||
Weighted-average discount rate | 4.98% | 5.19% | 2.72% | |||
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year | 6.50% | |||||
Pension Plan [Member] | ||||||
Assumptions for net periodic benefit cost: | ||||||
Weighted-average discount rate | 5.14% | 2.71% | 2.40% | |||
Expected long-term rate of return | 7.50% | 7% | 7.25% | |||
Assumptions for year-end funded status: | ||||||
Weighted-average discount rate | 4.98% | 5.18% | 2.71% | |||
Expected long-term rate of return | 7.50% | 7.50% | 7% | |||
Minimum [Member] | Forecast [Member] | ||||||
Defined Benefit Plan Disclosure [Line Items] | ||||||
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Thereafter | 4% | 4.70% | 3.20% | |||
Minimum [Member] | Pension Plan [Member] | ||||||
Assumptions for net periodic benefit cost: | ||||||
Rate of Compensation Increase | 4% | |||||
Assumptions for year-end funded status: | ||||||
Rate of Compensation Increase | 4% | 4% | ||||
Maximum [Member] | Forecast [Member] | ||||||
Defined Benefit Plan Disclosure [Line Items] | ||||||
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Thereafter | 4.70% | 5.80% | 4.60% | |||
Maximum [Member] | Pension Plan [Member] | ||||||
Assumptions for net periodic benefit cost: | ||||||
Rate of Compensation Increase | 5% | 3.50% | 3.50% | |||
Assumptions for year-end funded status: | ||||||
Rate of Compensation Increase | 4.73% | 6% | 3.50% |
Pension and Other Postretire_11
Pension and Other Postretirement Benefits Costs - Schedule of Future Employer Contributions and Benefit Payments (Details) - USD ($) $ in Thousands | 12 Months Ended | |||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 22, 2013 | |
Defined Benefit Plan Disclosure [Line Items] | ||||
Payment for Pension and Other Postretirement Benefits | $ 0 | |||
Expected future employer contributions | 20,600 | |||
Northwest Natural Gas Company [Member] | ||||
Defined Benefit Plan, Expected Future Benefit Payment [Abstract] | ||||
Defined Contribution Plan, Cost | 10,400 | $ 9,600 | $ 8,800 | |
Northwest Natural Gas Company [Member] | Western States Office and Professional Employees Union Pension Fund [Member] | ||||
Defined Benefit Plan, Expected Future Benefit Payment [Abstract] | ||||
Multiemployer Plan, Employer Contribution, Cost | 600 | $ 600 | $ 400 | |
Multiemployer Plan, Pension, Insignificant, Plan Contribution | 600 | |||
Multiemployer Plans, Withdrawal Obligation | 5,000 | $ 8,300 | ||
Northwest Natural Gas Company [Member] | Western States Office and Professional Employees Union Pension Fund [Member] | Maximum [Member] | ||||
Defined Benefit Plan, Expected Future Benefit Payment [Abstract] | ||||
Multiemployer Plan, Pension, Insignificant, Employer Contribution under Collective-Bargaining Arrangement to All Participating Employer Contributions, Percentage | 4% | 4% | ||
Northwest Natural Gas Company [Member] | Western States Office and Professional Employees Union Pension Fund [Member] | Minimum [Member] | ||||
Defined Benefit Plan, Expected Future Benefit Payment [Abstract] | ||||
Multiemployer Plan, Pension, Insignificant, Employer Contribution under Collective-Bargaining Arrangement to All Participating Employer Contributions, Percentage | 1% | 1% | ||
Northwest Natural Gas Company [Member] | Pension Plan [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Payment for Pension and Other Postretirement Benefits | 2,269 | $ 2,353 | ||
Expected future employer contributions | 22,850 | |||
Benefits paid | 27,970 | 27,563 | $ 25,371 | |
Defined Benefit Plan, Expected Future Benefit Payment [Abstract] | ||||
Year 1 | 27,288 | |||
Year 2 | 36,313 | |||
Year 3 | 27,979 | |||
Year 4 | 28,300 | |||
Year 6 | 28,604 | |||
Thereafter | 145,652 | |||
Northwest Natural Gas Company [Member] | Other Postretirement Benefits Plan [Member] | ||||
Defined Benefit Plan Disclosure [Line Items] | ||||
Payment for Pension and Other Postretirement Benefits | 1,793 | 2,026 | ||
Expected future employer contributions | 3,233 | |||
Benefits paid | 1,793 | $ 2,026 | $ 2,050 | |
Defined Benefit Plan, Expected Future Benefit Payment [Abstract] | ||||
Year 1 | 3,233 | |||
Year 2 | 1,652 | |||
Year 3 | 1,620 | |||
Year 4 | 1,608 | |||
Year 6 | 1,583 | |||
Thereafter | $ 7,440 |
Income Tax (Details)
Income Tax (Details) - USD ($) | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Regulatory Assets [Line Items] | |||
Unrecognized Tax Benefits | $ 0 | $ 0 | $ 0 |
Deferred Tax Liabilities, Property, Plant and Equipment | 350,802,000 | 326,326,000 | |
Deferred Tax Liabilities, Leasing Arrangements | 35,635,000 | 36,873,000 | |
Deferred Tax Liabilities, Lease Right of Use Assets | 21,002,000 | 21,272,000 | |
Deferred Tax Liabilities, Intangible Assets | 528,000 | 0 | |
Deferred Tax Liabilities Non Regulated Liabilities | 4,432,000 | 17,050,000 | |
Deferred Tax Liabilities, Net | 382,673,000 | 366,022,000 | |
Deferred Tax Assets, Lease Liabilities | 21,047,000 | 21,306,000 | |
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax | 56,000 | ||
Deferred Tax Assets, Tax Credit Carryforwards, Other | 76,000 | 101,000 | |
Deferred Tax Assets, Net of Valuation Allowance | 67,495,000 | 71,624,000 | |
Regulatory Liability, Noncurrent | 695,896,000 | 689,578,000 | |
Deferred Tax Assets, Goodwill and Intangible Assets | 0 | 1,947,000 | |
Deferred Tax Liabilities, Gross | 450,168,000 | 437,646,000 | |
Effective Income Tax Rate Reconciliation, Amount [Abstract] | |||
Income Tax Reconciliation, Income Tax Expense (Benefit), at Federal Statutory Income Tax Rate | 26,508,000 | 24,241,000 | 22,275,000 |
Income Tax Reconciliation, State and Local Income Taxes, net of federal tax benefit | 10,875,000 | 10,139,000 | 9,962,000 |
Income Tax Reconciliation, Differences Regulatory Commission | (3,976,000) | (4,748,000) | (4,655,000) |
Income Tax Reconciliation, Other Adjustments | (1,045,000) | (502,000) | (176,000) |
Income Tax Expense (Benefit) | $ 32,362,000 | $ 29,130,000 | $ 27,406,000 |
Effective Income Tax Rate | 25.60% | 25.20% | 25.80% |
Tax Provision Current And Deferred [Abstract] | |||
Current Federal Tax Expense (Benefit) | $ 13,496,000 | $ 5,172,000 | $ 6,508,000 |
Current State and Local Tax Expense (Benefit) | 9,901,000 | 6,551,000 | 6,281,000 |
Current Income Tax Expense (Benefit) | 23,397,000 | 11,723,000 | 12,789,000 |
Deferred Federal Income Tax Expense (Benefit) | 5,100,000 | 11,124,000 | 8,289,000 |
Deferred State and Local Income Tax Expense (Benefit) | 3,865,000 | 6,283,000 | 6,328,000 |
Deferred Income Tax Expense (Benefit) | 8,965,000 | 17,407,000 | 14,617,000 |
Income Tax Expense (Benefit) | 32,362,000 | 29,130,000 | 27,406,000 |
Tax Provision Regulated And Nonutility [Abstract] | |||
Income Tax Expense (Benefit) | 32,362,000 | 29,130,000 | 27,406,000 |
Pension Plan [Member] | |||
Regulatory Assets [Line Items] | |||
Deferred Tax Liabilities, Regulatory Assets | 24,830,000 | 22,973,000 | |
Income taxes [Member] | |||
Regulatory Assets [Line Items] | |||
Deferred Tax Liabilities, Regulatory Assets | 12,939,000 | 13,152,000 | |
Deferred Tax Assets, Regulatory Assets and Liabilities | 46,372,000 | 48,270,000 | |
Tax Provision Regulated And Nonutility [Abstract] | |||
Deferred Tax Assets, Regulatory Assets and Liabilities | 46,372,000 | 48,270,000 | |
Northwest Natural Gas Company [Member] | |||
Regulatory Assets [Line Items] | |||
Deferred Tax Liabilities, Property, Plant and Equipment | 340,042,000 | 320,121,000 | |
Deferred Tax Liabilities, Leasing Arrangements | 35,635,000 | 36,873,000 | |
Deferred Tax Liabilities, Lease Right of Use Assets | 20,849,000 | 21,084,000 | |
Deferred Tax Liabilities, Intangible Assets | 0 | 0 | |
Deferred Tax Liabilities Non Regulated Liabilities | 4,620,000 | 17,314,000 | |
Deferred Tax Liabilities, Net | 371,867,000 | 362,353,000 | |
Deferred Tax Assets, Lease Liabilities | 20,884,000 | 21,102,000 | |
Deferred Tax Assets, Tax Credit Carryforwards, Other | 44,000 | 44,000 | |
Deferred Tax Assets, Net of Valuation Allowance | 67,048,000 | 69,164,000 | |
Regulatory Liability, Noncurrent | 694,947,000 | 688,599,000 | |
Deferred Tax Assets, Goodwill and Intangible Assets | 0 | 0 | |
Deferred Tax Liabilities, Gross | 438,915,000 | 431,517,000 | |
Effective Income Tax Rate Reconciliation, Amount [Abstract] | |||
Income Tax Reconciliation, Income Tax Expense (Benefit), at Federal Statutory Income Tax Rate | 29,486,000 | 25,746,000 | 22,996,000 |
Income Tax Reconciliation, State and Local Income Taxes, net of federal tax benefit | 11,510,000 | 10,504,000 | 10,150,000 |
Income Tax Reconciliation, Differences Regulatory Commission | (3,972,000) | (4,746,000) | (4,738,000) |
Income Tax Reconciliation, Other Adjustments | (1,352,000) | (468,000) | (75,000) |
Income Tax Expense (Benefit) | $ 35,672,000 | $ 31,036,000 | $ 28,333,000 |
Effective Income Tax Rate | 25.40% | 25.30% | 25.90% |
Tax Provision Current And Deferred [Abstract] | |||
Current Federal Tax Expense (Benefit) | $ 20,512,000 | $ 7,442,000 | $ 7,570,000 |
Current State and Local Tax Expense (Benefit) | 12,304,000 | 7,307,000 | 7,540,000 |
Current Income Tax Expense (Benefit) | 32,816,000 | 14,749,000 | 15,110,000 |
Deferred Federal Income Tax Expense (Benefit) | 591,000 | 10,298,000 | 7,915,000 |
Deferred State and Local Income Tax Expense (Benefit) | 2,265,000 | 5,989,000 | 5,308,000 |
Deferred Income Tax Expense (Benefit) | 2,856,000 | 16,287,000 | 13,223,000 |
Income Tax Expense (Benefit) | 35,672,000 | 31,036,000 | 28,333,000 |
Tax Provision Regulated And Nonutility [Abstract] | |||
Income Tax Expense (Benefit) | 35,672,000 | 31,036,000 | $ 28,333,000 |
Northwest Natural Gas Company [Member] | Income taxes [Member] | Equity Portion, AFUDC | |||
Regulatory Assets [Line Items] | |||
Regulatory Assets | 4,900,000 | 2,900,000 | |
Northwest Natural Gas Company [Member] | Pension Plan [Member] | |||
Regulatory Assets [Line Items] | |||
Deferred Tax Liabilities, Regulatory Assets | 24,830,000 | 22,973,000 | |
Northwest Natural Gas Company [Member] | Income taxes [Member] | |||
Regulatory Assets [Line Items] | |||
Deferred Tax Liabilities, Regulatory Assets | 12,939,000 | 13,152,000 | |
Deferred Tax Assets, Regulatory Assets and Liabilities | 46,120,000 | 48,018,000 | |
Regulatory Liabilities | 174,200,000 | 181,400,000 | |
Regulatory Liability, Noncurrent | 169,485,000 | 174,212,000 | |
Tax Provision Regulated And Nonutility [Abstract] | |||
Deferred Tax Assets, Regulatory Assets and Liabilities | 46,120,000 | 48,018,000 | |
Excluding AFUDC [Member] | Northwest Natural Gas Company [Member] | Income taxes [Member] | |||
Regulatory Assets [Line Items] | |||
Regulatory Assets | 8,000,000 | $ 10,200,000 | |
Domestic Tax Authority [Member] | |||
Regulatory Assets [Line Items] | |||
Operating Loss Carryforwards | 29,000 | ||
State and Local Jurisdiction [Member] | |||
Regulatory Assets [Line Items] | |||
Operating Loss Carryforwards | $ 29,000 |
Property, Plant and Equipment_2
Property, Plant and Equipment (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Property, Plant and Equipment, Net, by Type [Abstract] | |||
Property, Plant and Equipment, Gross | $ 4,556,609 | $ 4,261,566 | |
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment | 1,198,555 | 1,147,166 | |
Total property, plant, and equipment, net | 3,358,054 | 3,114,400 | |
Property, Plant, Equipment non-cash | 27,879 | 25,318 | |
Regulatory Liability, Noncurrent | 695,896 | 689,578 | |
Asset Removal Costs [Member] | |||
Property, Plant and Equipment, Net, by Type [Abstract] | |||
Regulatory Liability, Noncurrent | 496,200 | 467,700 | |
Natural Gas Distribution [Member] | |||
Property, Plant and Equipment, Net, by Type [Abstract] | |||
Property, Plant and Equipment, Gross | 4,206,455 | 3,992,676 | |
Public Utilities, Property, Plant and Equipment, Construction Work in Progress | 105,166 | 78,897 | |
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment | 1,159,367 | 1,115,690 | |
Total property, plant, and equipment, net | 3,152,254 | 2,955,883 | |
Other Northwest Natural [Member] | |||
Property, Plant and Equipment, Net, by Type [Abstract] | |||
Property, Plant and Equipment, Gross | 71,175 | 70,368 | |
Public Utilities, Property, Plant and Equipment, Construction Work in Progress | 10,963 | 6,606 | |
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment | 22,595 | 21,541 | |
Total property, plant, and equipment, net | 59,543 | 55,433 | |
Northwest Natural Gas Company [Member] | |||
Property, Plant and Equipment, Net, by Type [Abstract] | |||
Total property, plant, and equipment, net | 3,211,797 | 3,011,316 | |
Property, Plant, Equipment non-cash | 24,168 | 24,584 | |
Northwest Holdings Other [Member] | |||
Property, Plant and Equipment, Net, by Type [Abstract] | |||
Property, Plant and Equipment, Gross | 147,040 | 92,979 | |
Public Utilities, Property, Plant and Equipment, Construction Work in Progress | 15,810 | 20,040 | |
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment | 16,593 | 9,935 | |
Total property, plant, and equipment, net | $ 146,257 | $ 103,084 | |
Natural Gas Distribution [Member] | |||
Property, Plant and Equipment, Net, by Type [Abstract] | |||
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 3% | 3% | 3% |
Other Northwest Natural [Member] | |||
Property, Plant and Equipment, Net, by Type [Abstract] | |||
Weighted Average Depreciation Rates | 1.70% | 1.80% | 1.80% |
Northwest Natural Gas Company [Member] | |||
Property, Plant and Equipment, Net, by Type [Abstract] | |||
Property, Plant and Equipment, Gross | $ 4,393,759 | $ 4,148,547 | |
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment | 1,181,962 | 1,137,231 | |
Total property, plant, and equipment, net | 3,211,797 | 3,011,316 | |
Regulatory Liability, Noncurrent | 694,947 | 688,599 | |
Northwest Natural Gas Company [Member] | Asset Removal Costs [Member] | |||
Property, Plant and Equipment, Net, by Type [Abstract] | |||
Regulatory Liability, Noncurrent | $ 496,235 | $ 467,742 |
Investments (Details)
Investments (Details) $ in Thousands | 12 Months Ended | ||||
Dec. 31, 2023 USD ($) numberOfEmployees numberOfProjects numberOfCustomerConnections | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Jan. 31, 2024 USD ($) | Jun. 30, 2023 USD ($) | |
Schedule of Investments [Line Items] | |||||
Total Cumulative Gas Reserves Investment | $ 188,000 | ||||
Other Investments [Abstract] | |||||
Life Insurance, Corporate or Bank Owned, Amount | 45,713 | $ 49,358 | |||
Inventory, Gas in Storage Underground, Noncurrent | 20,893 | 22,970 | |||
Equity Method Investment, Aggregate Cost | 36,345 | 23,376 | |||
Total Other investments | 102,951 | 95,704 | |||
Investments in Unconsolidated Affiliates [Abstract] | |||||
Proceeds from Sale of Equity Method Investments | $ 0 | 0 | $ 7,000 | ||
Investments, Number of RNG Development Projects | numberOfProjects | 4 | ||||
Northwest Holdings Other [Member] | Avion Water | |||||
Investments in Unconsolidated Affiliates [Abstract] | |||||
Ownership percentage | 37.30% | 43.10% | |||
Equity Method Investment, Underlying Equity in Net Assets | $ 14,500 | ||||
Equity Method Investment, Number of Customer Connections | numberOfCustomerConnections | 15,000 | ||||
Equity Method Investment, Number of Employees | numberOfEmployees | 35 | ||||
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity | $ 8,600 | ||||
Equity Method Investment, Additional Underlying Equity in Net Assets | $ 1,000 | ||||
Northwest Holdings Other [Member] | Avion Water | Subsequent Event [Member] | |||||
Investments in Unconsolidated Affiliates [Abstract] | |||||
Ownership percentage | 45.60% | ||||
Equity Method Investment, Additional Underlying Equity in Net Assets | $ 1,000 | ||||
Northwest Natural Gas Company [Member] | |||||
Other Investments [Abstract] | |||||
Total Other investments | 86,145 | 80,110 | |||
Investments in Unconsolidated Affiliates [Abstract] | |||||
Deferred Taxes Related To Gas Reserves | $ 4,000 | $ 5,200 | |||
Gas Reserves Percent Gas Supplies YTD | 3% | 3% | |||
Deferred Gas Cost | $ 2,300 | $ 3,400 | |||
Northwest Natural Gas Company [Member] | |||||
Other Investments [Abstract] | |||||
Life Insurance, Corporate or Bank Owned, Amount | 45,713 | 49,358 | |||
Inventory, Gas in Storage Underground, Noncurrent | 20,893 | 22,970 | |||
Equity Method Investment, Aggregate Cost | 19,539 | 7,782 | |||
Total Other investments | 86,145 | $ 80,110 | |||
Northwest Natural Gas Company [Member] | Lexington | |||||
Other Investments [Abstract] | |||||
Equity Method Investment, Aggregate Cost | 7,600 | ||||
Northwest Natural Gas Company [Member] | Dakota City | |||||
Other Investments [Abstract] | |||||
Equity Method Investment, Aggregate Cost | 11,900 | ||||
Investments in Unconsolidated Affiliates [Abstract] | |||||
Deconsolidation, Gain (Loss), Amount | $ 0 |
Business Combinations (Details)
Business Combinations (Details) | 12 Months Ended | |||
Dec. 31, 2023 USD ($) multiplier connections | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) numberOfConnections | Oct. 05, 2022 USD ($) | |
Business Acquisition [Line Items] | ||||
Business Combination, Consideration Transferred | $ 22,800,000 | |||
Goodwill | 163,344,000 | $ 149,283,000 | ||
Goodwill, Impairment Loss | 0 | |||
Operating revenues | $ 1,197,475,000 | 1,037,353,000 | $ 860,400,000 | |
Average Annual System Operating Revenue Multiplier, Contingent Consideration | multiplier | 4 | |||
Business Combinations | BUSINESS COMBINATIONS 2023 Business Combinations During the year ended December 31, 2023, NWN Water and its subsidiaries acquired the assets of five businesses qualifying as business combinations. The aggregate fair value of the preliminary total consideration transferred for these acquisitions was $22.8 million, most of which was preliminarily allocated to property, plant, and equipment, and goodwill. These transactions align with NW Holdings' water and wastewater sector strategy as it continues to expand its water and wastewater service territories and included: • Pedersen Family, LLC in Washington • King Water Corporation in Washington • Rose Valley Water Company in Arizona • Hiland Water in Oregon • Truxton and Cerbat in Arizona Intangible Assets In connection with the acquisition of King Water Corporation, NWN Water recorded long-term customer relationship intangible assets totaling $2.6 million, which will be amortized over 24 years. There was no amortization expense recognized in 2023. Projected amortization expense at NW Holdings for customer relationship intangible assets for each of the next five years is $0.1 million in each period. The amortization will change in future periods if other intangible assets are acquired, impairments are recognized or the preliminary valuations as part of our purchase price allocation is refined. 2022 Business Combinations Far West Water & Sewer, Inc. On October 5, 2022, NWN Water completed the acquisition of the water and wastewater utilities of Far West Water & Sewer, Inc. (Far West), which has a combined approximately 25,000 connections in Yuma, Arizona. The acquisition-date fair value of the total consideration transferred, after closing adjustments, was approximately $97.0 million, of which $88.4 million was cash consideration transferred at closing, $8.1 million was contingent consideration, and $0.5 million was deferred consideration. The contingent consideration is an earnout payment in an amount equal to the product of (i) the amount, if any, by which the average annual System Operating Revenue for the 2026, 2027, and 2028 years exceeds $13.0 million (ii) multiplied by 4 but shall not exceed $12.0 million. As of the acquisition date, the contingent consideration had a fair value of $8.1 million and was included in other non-current liabilities. The fair value as of the acquisition date was determined using a scenario-based technique using management's best estimate of forecast revenue for the years 2026, 2027, and 2028 discounted to present value. The inputs to determine the fair value of the contingent consideration include estimated future revenue and a risk-adjusted discount rate. The fair value measurement is based on significant inputs that are not observable in the market and thus represents a fair value measurement categorized within Level 3 of the fair value hierarchy per ASC Topic 820. The Far West acquisition met the criteria of a business combination, and as such an allocation of the consideration to the acquired net assets based on their estimated fair value as of the acquisition date was performed. In accordance with U.S. GAAP, the fair value determination involves management judgment in determining the significant estimates and assumptions used and was made using existing regulatory conditions for net assets associated with Far West. The acquisition costs were expensed as incurred. Goodwill of $69.9 million was recognized from this acquisition. The goodwill recognized is attributable to Far West's regulated water utility service territory, experienced workforce, and the strategic benefits for both the water utility and wastewater services expected from growth in its service territory. No intangible assets aside from goodwill were recognized. The amount of goodwill that is expected to be deductible for income tax purposes is approximately $63.3 million. The purchase price for the acquisition has been allocated to the net assets acquired as of the acquisition date and is as follows: In thousands December 31, 2023 Current assets $ 1,569 Property, plant and equipment 25,974 Goodwill 69,890 Non-current assets 1,077 Current liabilities (991) Non-current liabilities (9,115) Total net assets acquired $ 88,404 The amount of Far West revenues included in NW Holdings' consolidated statements of comprehensive income is $2.9 million for the year ended December 31, 2022. Earnings from Far West activities for the year ended December 31, 2022 were not material to the results of NW Holdings. Far West is referred to as Foothills Utilities following the closure of the acquisition. Other 2022 Business Combinations During the year ended December 31, 2022, NWN Water and its subsidiaries acquired the assets of six additional businesses qualifying as business combinations. The aggregate fair value of the consideration transferred for these acquisitions was $8.7 million, most of which was allocated to property, plant and equipment and goodwill. These transactions align with NW Holdings' water and wastewater sector strategy as it continues to expand its water and wastewater service territories and included: • Belle Oaks Water and Sewer Co., Inc in Texas • Northwest Water Services, LLC in Washington • Aquarius Utilities, LLC in Washington • Valiant Idaho, LLC (The Idaho Club - Sewer) in Idaho • Caney Creek in Texas • Water Necessities, Inc. and Rural Water Co. in Texas 2021 Business Combinations During the year ended December 31, 2021, NWN Water and its subsidiaries completed four acquisitions qualifying as business combinations. The aggregate fair value of the consideration transferred for these acquisitions were not material and are not significant to NW Holdings' results of operations. Goodwill NW Holdings allocates goodwill to reporting units based on the expected benefit from the business combination. We perform an annual impairment assessment of goodwill at the reporting unit level, or more frequently if events and circumstances indicate that goodwill might be impaired. An impairment loss is recognized if the carrying value of a reporting unit’s goodwill exceeds its fair value. As a result of all acquisitions completed, total goodwill was $163.3 million as of December 31, 2023 and $149.3 million as of December 31, 2022. The increase in the goodwill balance was primarily due to additions associated with our acquisitions in the water and wastewater sector. All of our goodwill is related to water and wastewater acquisitions and is included in the other category for segment reporting purposes. The annual impairment assessment of goodwill occurs in the fourth quarter of each year. There have been no impairments recognized to date. | |||
Customer-Related Intangible Assets | NWN Water | ||||
Business Acquisition [Line Items] | ||||
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles | $ 2,600,000 | |||
Finite-Lived Intangible Assets, Remaining Amortization Period | 24 years | |||
Amortization | $ 0 | |||
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextFiveYears | $ 100,000 | |||
Other insignificant acquisitions [Member] | ||||
Business Acquisition [Line Items] | ||||
Business Combination, Consideration Transferred | $ 8,700,000 | |||
Number of Businesses Acquired | 5 | 6 | 4 | |
Far West Water & Sewer, Inc. | ||||
Business Acquisition [Line Items] | ||||
Business Combination, Consideration Transferred | $ 97,000,000 | |||
Goodwill | $ 69,890,000 | |||
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets | 1,077,000 | |||
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities | (991,000) | |||
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities | (9,115,000) | |||
Business Acquisition, Goodwill, Expected Tax Deductible Amount | 63,300,000 | |||
Cash Acquired from Acquisition | 88,404,000 | |||
Business Combination, Contingent Consideration, Liability | 8,100,000 | |||
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High | 12,000,000 | |||
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets | 1,569,000 | |||
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment | $ 25,974,000 | |||
Payments to Acquire Businesses, Gross | 88,400,000 | |||
Business Combination, Connections of Business Acquired | connections | 25,000 | |||
Average Annual System Operating Revenue Threshold, Contingent Consideration | $ 13,000,000 | |||
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual | $ 2,900,000 | |||
Far West Water & Sewer, Inc. | Fair Value of Contingent Consideration | ||||
Business Acquisition [Line Items] | ||||
Business Combination, Contingent Consideration, Liability | $ 8,100,000 | |||
Far West Water & Sewer, Inc. | Deferred Contingent Consideration | ||||
Business Acquisition [Line Items] | ||||
Business Combination, Contingent Consideration, Liability | $ 500,000 |
Derivative Instruments - Narrat
Derivative Instruments - Narrative (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Derivative [Line Items] | |||
Derivative, Fair Value, Net | $ (115,200) | $ 149,700 | |
Unrealized gain on interest rate swaps, net of taxes | 59 | 129 | $ 0 |
Derivative Credit Risk Valuation Adjustment, Derivative Liabilities | 700 | ||
Northwest Natural Gas Company [Member] | |||
Derivative [Line Items] | |||
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 9,000 | 153,300 | |
Derivative Liability, Fair Value, Amount Not Offset Against Collateral | $ 124,200 | $ 3,600 | |
Northwest Natural Gas Company [Member] | Gas Year 2020 - 2021 | |||
Derivative [Line Items] | |||
TargetHedgeAchieved | 84% | ||
Northwest Natural Gas Company [Member] | Gas Year 2020 - 2021 | Oregon [Member] | |||
Derivative [Line Items] | |||
TargetHedgeAchieved | 85% | ||
Northwest Natural Gas Company [Member] | Gas Year 2020 - 2021 | WASHINGTON | |||
Derivative [Line Items] | |||
TargetHedgeAchieved | 79% | ||
Northwest Natural Gas Company [Member] | Gas Year 2020 - 2021 | Financial [Member] | |||
Derivative [Line Items] | |||
TargetHedgeAchieved | 67% | ||
Northwest Natural Gas Company [Member] | Gas Year 2020 - 2021 | Physical [Member] | |||
Derivative [Line Items] | |||
TargetHedgeAchieved | 17% | ||
Northwest Natural Gas Company [Member] | Gas Year 2021 - 2022 | |||
Derivative [Line Items] | |||
TargetHedgeAchieved | 82% | ||
Northwest Natural Gas Company [Member] | Gas Year 2021 - 2022 | Oregon [Member] | |||
Derivative [Line Items] | |||
TargetHedgeAchieved | 85% | ||
Northwest Natural Gas Company [Member] | Gas Year 2021 - 2022 | WASHINGTON | |||
Derivative [Line Items] | |||
TargetHedgeAchieved | 55% | ||
Northwest Natural Gas Company [Member] | Gas Year 2021 - 2022 | Financial [Member] | |||
Derivative [Line Items] | |||
TargetHedgeAchieved | 66% | ||
Northwest Natural Gas Company [Member] | Gas Year 2021 - 2022 | Physical [Member] | |||
Derivative [Line Items] | |||
TargetHedgeAchieved | 16% |
Derivative Instruments - Schedu
Derivative Instruments - Schedule of Notional Amounts (Details) - Northwest Natural Gas Company [Member] therm in Thousands, $ in Thousands | Dec. 31, 2023 USD ($) therm | Dec. 31, 2022 USD ($) therm |
Natural Gas Therms [Member] | Financial [Member] | ||
Derivative [Line Items] | ||
Derivative, Nonmonetary Notional Amount | 948,425 | 852,435 |
Natural Gas Therms [Member] | Physical [Member] | ||
Derivative [Line Items] | ||
Derivative, Nonmonetary Notional Amount | 571,610 | 463,254 |
Foreign Exchange Contract [Member] | ||
Derivative [Line Items] | ||
Derivative, Notional Amount | $ | $ 11,926 | $ 7,617 |
Derivative Instruments - Sche_2
Derivative Instruments - Schedule of Unrealized and Realized Gain/Loss (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2023 | Dec. 31, 2022 | |
General Discussion of Derivative Instruments and Hedging Activities [Abstract] | ||
Derivative, Gain, Statement of Income or Comprehensive Income [Extensible Enumeration] | Operating revenues | Operating revenues |
AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax | $ 200 | $ 100 |
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion | 0 | |
Northwest Holdings and Northwest Natural [Member] | Foreign Exchange Contract [Member] | ||
Derivative [Line Items] | ||
Gain (Loss) on Derivative Instruments, Net, Pretax | 0 | 0 |
Northwest Holdings and Northwest Natural [Member] | Foreign Exchange Contract [Member] | Cost of Sales [Member] | ||
Derivative [Line Items] | ||
Gain (Loss) on Derivative Instruments, Net, Pretax | 168 | (165) |
Northwest Holdings and Northwest Natural [Member] | Foreign Exchange Contract [Member] | Sales [Member] | ||
Derivative [Line Items] | ||
Gain (Loss) on Derivative Instruments, Net, Pretax | 0 | 0 |
Northwest Holdings and Northwest Natural [Member] | Natural Gas Commodity [Member] | ||
Derivative [Line Items] | ||
Gain (Loss) on Derivative Instruments, Net, Pretax | 0 | 0 |
Northwest Holdings and Northwest Natural [Member] | Natural Gas Commodity [Member] | Cost of Sales [Member] | ||
Derivative [Line Items] | ||
Gain (Loss) on Derivative Instruments, Net, Pretax | (131,833) | (119,935) |
Northwest Holdings and Northwest Natural [Member] | Natural Gas Commodity [Member] | Sales [Member] | ||
Derivative [Line Items] | ||
Gain (Loss) on Derivative Instruments, Net, Pretax | 0 | 0 |
Northwest Holdings and Northwest Natural [Member] | Deferred Derivative Gain (Loss) [Member] | Foreign Exchange Contract [Member] | ||
Derivative [Line Items] | ||
Gain (Loss) on Derivative Instruments, Net, Pretax | (168) | 165 |
Northwest Holdings and Northwest Natural [Member] | Deferred Derivative Gain (Loss) [Member] | Natural Gas Commodity [Member] | ||
Derivative [Line Items] | ||
Gain (Loss) on Derivative Instruments, Net, Pretax | $ 131,833 | $ (119,935) |
- Schedule of Credit Rating Dow
- Schedule of Credit Rating Downgrade Scenarios (Details) - USD ($) | Dec. 31, 2023 | Dec. 31, 2022 |
Collateral Posted with NW Natural Counterparties [Member] | ||
Derivative [Line Items] | ||
Collateral Already Posted, Aggregate Fair Value | $ 0 | $ 0 |
Commitments and Contingencies -
Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Leases [Abstract] | |||
Property, Plant and Equipment, Gross | $ 4,556,609 | $ 4,261,566 | |
Other Liabilities, Noncurrent | $ 119,034 | 123,438 | |
Maximum [Member] | |||
Leases [Abstract] | |||
Lessee, Operating Lease, Term of Contract | 16 years | ||
Northwest Natural Gas Company [Member] | |||
Leases [Abstract] | |||
Unrecorded Unconditional Purchase Obligation, Purchases | $ 87,000 | 90,200 | $ 82,900 |
Unrecorded Unconditional Purchase Obligation Offsetting Sales | 8,200 | 8,300 | $ 7,700 |
Property, Plant and Equipment, Gross | 4,393,759 | 4,148,547 | |
Other Liabilities, Noncurrent | $ 109,066 | $ 114,527 |
Commitments and Contingencies_2
Commitments and Contingencies - Schedule of Gas Purchase and Pipeline Capacity Purchase and Release Commitments (Details) - Northwest Natural Gas Company [Member] $ in Thousands | Dec. 31, 2023 USD ($) |
Gas Purchase Agreements [Member] | |
Unrecorded Unconditional Purchase Obligation [Line Items] | |
2018 | $ 303,682 |
2019 | 34,457 |
2020 | 34,586 |
2021 | 33,830 |
2022 | 33,980 |
Thereafter | 208,426 |
Total | 648,961 |
Less: Amount representing interest | 96,491 |
Total at present value | 552,470 |
Pipeline Capacity Purchase Agreements [Member] | |
Unrecorded Unconditional Purchase Obligation [Line Items] | |
2018 | 78,907 |
2019 | 81,114 |
2020 | 66,972 |
2021 | 67,123 |
2022 | 63,812 |
Thereafter | 377,175 |
Total | 735,103 |
Less: Amount representing interest | 183,620 |
Total at present value | 551,483 |
Pipeline Capacity Release Agreements [Member] | |
Unrecorded Unconditional Purchase Obligation [Line Items] | |
2018 | 7,543 |
2019 | 3,455 |
2020 | 0 |
2021 | 0 |
2022 | 0 |
Thereafter | 0 |
Total | 10,998 |
Less: Amount representing interest | 373 |
Total at present value | $ 10,625 |
Environmental Matters (Details)
Environmental Matters (Details) | 12 Months Ended | |
Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | |
Accrual for Environmental Loss Contingencies [Abstract] | ||
Insurance Proceeds Applied To Prudently Incurred Remediation Costs | $ 3,900,000 | |
Environmental Regulatory Table [Abstract] | ||
Regulatory Assets, Current | 178,270,000 | $ 117,491,000 |
Regulatory Assets, Noncurrent | $ 333,443,000 | 340,432,000 |
Insurance Proceeds, Amortization Period | 10 years 6 months | |
Cost Recovery Period | 3 years | |
Environmental Restoration Costs [Member] | Front Street [Member] | ||
Environmental Regulatory Table [Abstract] | ||
Environmental Regulatory Accrued Site Liabilities | $ 53,000 | 43,000 |
WASHINGTON | ||
Environmental Activity [Line Items] | ||
Remediation Recovery Percentage | 3.30% | |
Oregon [Member] | ||
Environmental Activity [Line Items] | ||
Remediation Recovery Percentage | 96.70% | |
Environmental Regulatory Table [Abstract] | ||
Remediation Non-Recovery Percentage | 3.30% | |
Northwest Natural Gas Company [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
Annual Tariff Rider Collection | $ 5,000,000 | |
Environmental Settlement Insurance Proceeds Received To Date | 150,000,000 | |
Annual insurance proceeds to appy against remediation costs | 5,000,000 | |
Insurance Proceeds Applied To Prudently Incurred Remediation Costs | 100,700,000 | |
Environmental Regulatory Table [Abstract] | ||
Regulatory Assets, Current | 178,270,000 | 117,491,000 |
Regulatory Assets, Noncurrent | 333,418,000 | $ 340,407,000 |
Annual Insurance Proceeds to Apply Against Remediation Costs | 5,000,000 | |
Total Annual Remediation Expense and Interest | $ 10,000,000 | |
Environmental Loss Contingency, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Other non-current liabilities | Other non-current liabilities |
Environmental Loss Contingency, Current, Statement of Financial Position [Extensible Enumeration] | Other current liabilities | Other current liabilities |
Northwest Natural Gas Company [Member] | Gasco Siltronic Sediments [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
Environmental Current Liabilities | $ 12,428,000 | $ 9,744,000 |
Environmental Noncurrent Liabilities | 42,550,000 | 42,120,000 |
Northwest Natural Gas Company [Member] | Portland Harbor Other [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
Environmental Current Liabilities | 3,035,000 | 2,634,000 |
Environmental Noncurrent Liabilities | 11,270,000 | 11,270,000 |
Northwest Natural Gas Company [Member] | Gasco Upland [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
Environmental Current Liabilities | 16,304,000 | 16,067,000 |
Environmental Noncurrent Liabilities | 34,235,000 | 35,457,000 |
Northwest Natural Gas Company [Member] | Front Street [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
Environmental Current Liabilities | 687,000 | 457,000 |
Environmental Noncurrent Liabilities | 939,000 | 879,000 |
Northwest Natural Gas Company [Member] | Oregon Steel Mills [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
Environmental Current Liabilities | 0 | 0 |
Environmental Noncurrent Liabilities | 179,000 | 179,000 |
Northwest Natural Gas Company [Member] | Environmental Restoration Costs [Member] | ||
Environmental Regulatory Table [Abstract] | ||
Environmental Regulatory Deferred Cost and Interest | 57,758,000 | 47,666,000 |
Environmental Regulatory Accrued Site Liabilities | 121,575,000 | 118,763,000 |
Environmental Regulatory Insurance Proceeds and Interest | (50,764,000) | (54,784,000) |
Regulatory Assets, Current | 9,950,000 | 7,392,000 |
Regulatory Assets, Noncurrent | 118,619,000 | 104,253,000 |
Regulatory Assets | 128,569,000 | $ 111,645,000 |
Front Street [Member] | Northwest Natural Gas Company [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
Liability For Studies And Design Costs | 1,600,000 | |
Portland Harbor [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
EPA Record Of Decision, Clean-Up Costs, Portland Harbor | $ 1,050,000,000 | |
Site Contingency, Number of Remediation Projects | 2 | |
Number Of Potentially Responsible Parties | one hundred | |
Portland Harbor [Member] | Minimum [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
EPA Record Of Decision, Clean-Up Costs, Portland Harbor | $ (0.30) | |
Portland Harbor [Member] | Maximum [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
EPA Record Of Decision, Clean-Up Costs, Portland Harbor | 0.50 | |
Gasco Siltronic Sediments [Member] | ||
Environmental Regulatory Table [Abstract] | ||
Environmental Exit Costs, Costs Accrued to Date | 55,000,000 | |
Gasco Siltronic Sediments [Member] | Minimum [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
Environmental Exit Costs, Anticipated Cost | 55,000,000 | |
Gasco Siltronic Sediments [Member] | Maximum [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
Environmental Exit Costs, Anticipated Cost | $ 350,000,000 | |
Yakama Nation [Member] | Portland Harbor Other [Member] | ||
Accrual for Environmental Loss Contingencies [Abstract] | ||
Trustee Council Members - Number of Claimants | 1 | |
Site Contingency, Number of Other Third-Party Defendants | 29 | |
NRD Liability Claim Yakama Nation | $ 300,000 | |
Number of Amended Complaints Filed | 2 |
Subsequent Events (Details)
Subsequent Events (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Aug. 04, 2023 | Dec. 31, 2022 | |
Note 5430 Series due 2053 | Northwest Natural Gas Company [Member] | |||
Subsequent Event [Line Items] | |||
Secured Debt | $ 100,000 | $ 0 | |
Debt Instrument, Interest Rate, Stated Percentage | 5.43% | 5.43% | |
Proceeds from Issuance of First Mortgage Bond | $ 100,000 | ||
Note 5180 Series due 2034 | |||
Subsequent Event [Line Items] | |||
Debt Instrument, Interest Rate, Stated Percentage | 5.18% | ||
Note 5180 Series due 2034 | Northwest Natural Gas Company [Member] | |||
Subsequent Event [Line Items] | |||
Secured Debt | $ 80,000 | $ 0 | |
Debt Instrument, Interest Rate, Stated Percentage | 5.18% | 5.18% | |
Proceeds from Issuance of First Mortgage Bond | $ 80,000 | ||
Note 5230 Series due 2038 | |||
Subsequent Event [Line Items] | |||
Debt Instrument, Interest Rate, Stated Percentage | 5.23% | ||
Note 5230 Series due 2038 | Northwest Natural Gas Company [Member] | |||
Subsequent Event [Line Items] | |||
Secured Debt | $ 50,000 | $ 50,000 | $ 0 |
Debt Instrument, Interest Rate, Stated Percentage | 5.23% | 5.23% |
Condensed Financials Standalo_3
Condensed Financials Standalone Holdco Condensed Financials Standalone Holdco (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Income Statement [Abstract] | |||
Operations and maintenance | $ 273,766 | $ 224,667 | $ 204,227 |
Total operating expenses | 1,012,534 | 869,876 | 697,283 |
Income (loss) from operations | 184,941 | 167,477 | 163,117 |
Other income (expense), net | 17,855 | 1,203 | (12,559) |
Interest expense, net | 76,566 | 53,247 | 44,486 |
Income (Loss) Attributable to Parent, before Tax | 126,230 | 115,433 | 106,072 |
Income Tax Expense (Benefit) | 32,362 | 29,130 | 27,406 |
Net income | 93,868 | 86,303 | 78,666 |
Unrealized gain on interest rate swaps, net of taxes | 59 | 129 | 0 |
Balance Sheet Related Disclosures [Abstract] | |||
Cash and cash equivalents | $ 32,920 | 29,270 | |
Receivables from affiliates - Affiliated Entity [Extensible Enumeration] | Affiliated Entity [Member] | ||
Other current assets | $ 65,275 | 61,286 | |
Total current assets | 601,440 | 744,213 | |
Other investments | 102,951 | 95,704 | |
Other non-current assets | 106,239 | 91,518 | |
Total non-current assets | 4,265,652 | 4,004,113 | |
Total assets | 4,867,092 | 4,748,326 | |
Short-term debt | 89,780 | 258,200 | |
Current maturities of long-term debt | 150,865 | 90,697 | |
Accounts payable | $ 145,361 | 180,667 | |
Payables to affiliates - Affiliated Entity [Extensible Enumeration] | Affiliated Entity [Member] | ||
Taxes accrued | $ 15,454 | 15,625 | |
Other current liabilities | 93,626 | 64,552 | |
Interest accrued | 15,836 | 10,169 | |
Total current liabilities | 696,878 | 898,734 | |
Long-term Debt | 1,576,300 | 1,336,864 | |
Long-term debt | (1,425,435) | (1,246,167) | |
Total deferred credits and other non-current liabilities | 1,460,941 | 1,427,984 | |
Common stock - no par value | 890,976 | 805,253 | |
Retained earnings | 399,911 | 376,473 | |
Total equity | 1,283,838 | 1,175,441 | |
Total liabilities and equity | 4,867,092 | 4,748,326 | |
Statement of Cash Flows [Abstract] | |||
Net income | 93,868 | 86,303 | 78,666 |
Deferred income taxes | 8,966 | 17,410 | 14,617 |
Other | (22,972) | (21,558) | (20,622) |
Receivables, net | (50,977) | 76,454 | 44,128 |
Income and other taxes | (1,246) | 6,908 | 3,292 |
Accounts payable | (39,958) | 24,508 | 12,118 |
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract] | |||
Other, net | 18,445 | (12,351) | (18,662) |
Cash provided by operating activities | 279,949 | 147,672 | 160,353 |
Net Cash Provided by (Used in) Investing Activities | (335,497) | (435,460) | (300,123) |
Proceeds from Issuance of Common Stock | 66,495 | 208,561 | 17,501 |
Changes in other short-term debt, net | (168,540) | (131,300) | 280,000 |
Cash dividend payments on common stock | (67,340) | (62,771) | (55,919) |
Other | (4,207) | (1,946) | (1,222) |
Cash provided by (used in) financing activities | 64,208 | 301,632 | 131,436 |
Increase (decrease) in cash and cash equivalents | 8,660 | 13,844 | (8,334) |
Cash, cash equivalents and restricted cash, beginning of period | 29,270 | ||
Cash, cash equivalents and restricted cash, end of period | 32,920 | 29,270 | |
Total Dividends Paid to Registrant, Consolidated Subsidiaries | 95,700 | 62,700 | 82,100 |
Comprehensive income (loss) | 93,104 | 91,422 | 80,164 |
Parent Company, Condensed Statement of Cash Flows [Member] | |||
Income Statement [Abstract] | |||
Equity in earnings of subsidiaries, net of tax | 106,267 | 92,727 | 83,072 |
Net income | 93,868 | 86,303 | 78,666 |
Balance Sheet Related Disclosures [Abstract] | |||
Cash and cash equivalents | 1,011 | 7,280 | 265 |
Long-term Debt | 0 | 100,000 | 0 |
Statement of Cash Flows [Abstract] | |||
Net income | 93,868 | 86,303 | 78,666 |
Equity in earnings of subsidiaries, net of tax | 106,267 | 92,727 | 83,072 |
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Consolidated Subsidiaries | 92,375 | 62,710 | 56,057 |
Deferred income taxes | (31) | (141) | (212) |
Other | 164 | 142 | 119 |
Receivables, net | (5,629) | (7,787) | 12,558 |
Income and other taxes | (491) | 8,161 | 1,299 |
Accounts payable | 6,314 | (2,499) | 3,342 |
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract] | |||
Increase (Decrease) in Interest Payable, Net | 103 | 156 | 57 |
Other, net | 380 | 211 | 313 |
Cash provided by operating activities | 80,026 | 54,107 | 68,501 |
Contributions to subsidiaries | (76,310) | (241,497) | (142,405) |
Proceeds from Equity Method Investment, Distribution, Return of Capital | 3,350 | 0 | 26,000 |
Net Cash Provided by (Used in) Investing Activities | (72,960) | (241,497) | (116,405) |
Proceeds from Issuance of Common Stock | 66,495 | 208,561 | 17,501 |
Changes in other short-term debt, net | (15,000) | (56,000) | 71,000 |
Cash dividend payments on common stock | (67,340) | (62,771) | (55,919) |
Other | 2,510 | 4,615 | 4,320 |
Cash provided by (used in) financing activities | (13,335) | 194,405 | 36,902 |
Increase (decrease) in cash and cash equivalents | (6,269) | 7,015 | (11,002) |
Cash, cash equivalents and restricted cash, beginning of period | 7,280 | 265 | 11,267 |
Cash, cash equivalents and restricted cash, end of period | 1,011 | 7,280 | 265 |
Parent Company, Condensed Balance Sheet [Member] | |||
Balance Sheet Related Disclosures [Abstract] | |||
Cash and cash equivalents | 1,011 | 7,280 | |
Receivables from affiliates | 15,596 | 9,967 | |
Other current assets | 4,160 | 2,895 | |
Total current assets | 20,767 | 20,142 | |
Investments in subsidiaries | 1,456,449 | 1,357,599 | |
Other investments | 32 | 14 | |
Deferred Income Tax Assets, Net | 513 | 520 | |
Other non-current assets | 367 | 486 | |
Total non-current assets | 1,457,361 | 1,358,619 | |
Total assets | 1,478,128 | 1,378,761 | |
Short-term debt | 73,000 | 88,000 | |
Current maturities of long-term debt | 99,992 | 0 | |
Accounts payable | 968 | 402 | |
Payables to affiliates | 19,897 | 14,665 | |
Other current liabilities | 433 | 295 | |
Total current liabilities | 194,290 | 103,362 | |
Long-term Debt | 0 | 99,958 | |
Total equity | 1,283,838 | 1,175,441 | |
Total liabilities and equity | 1,478,128 | 1,378,761 | |
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract] | |||
Cash, cash equivalents and restricted cash, beginning of period | 7,280 | ||
Cash, cash equivalents and restricted cash, end of period | 1,011 | 7,280 | |
Parent Company, Condensed Income Statement [Member] | |||
Income Statement [Abstract] | |||
Operations and maintenance | 5,145 | 3,828 | 4,837 |
Total operating expenses | 5,145 | 3,828 | 4,837 |
Income (loss) from operations | (5,145) | (3,828) | (4,837) |
Equity in earnings of subsidiaries, net of tax | (106,267) | (92,727) | (83,072) |
Other income (expense), net | (1,156) | 60 | (143) |
Interest expense, net | 10,022 | 4,967 | 982 |
Income (Loss) Attributable to Parent, before Tax | 89,944 | 83,992 | 77,110 |
Income Tax Expense (Benefit) | (3,924) | (2,311) | (1,556) |
Net income | 93,868 | 86,303 | 78,666 |
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent | (868) | 5,108 | 1,498 |
Unrealized gain on interest rate swaps, net of taxes | 104 | 11 | 0 |
Statement of Cash Flows [Abstract] | |||
Net income | 93,868 | 86,303 | 78,666 |
Equity in earnings of subsidiaries, net of tax | (106,267) | (92,727) | (83,072) |
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract] | |||
Comprehensive income (loss) | $ 93,104 | $ 91,422 | $ 80,164 |
Valuation Allowances and Rese_3
Valuation Allowances and Reserves (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Entity Information [Line Items] | |||
Allowance for Doubtful Accounts Receivable, beginning of period | $ 3,296 | $ 2,018 | $ 3,219 |
Valuation Allowances and Reserves, Charged to Cost and Expense | 2,869 | 1,081 | 724 |
Valuation Allowances and Reserves, Charged to Other Accounts | 263 | 1,810 | (219) |
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction | 2,973 | 1,613 | 1,706 |
Allowance for Doubtful Accounts Receivable, end of period | 3,455 | 3,296 | 2,018 |
Northwest Natural Gas Company [Member] | |||
Entity Information [Line Items] | |||
Allowance for Doubtful Accounts Receivable, beginning of period | 3,079 | 1,962 | 3,107 |
Valuation Allowances and Reserves, Charged to Cost and Expense | 2,859 | 920 | 780 |
Valuation Allowances and Reserves, Charged to Other Accounts | 263 | 1,810 | (219) |
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction | 2,973 | 1,613 | 1,706 |
Allowance for Doubtful Accounts Receivable, end of period | $ 3,228 | $ 3,079 | $ 1,962 |