v3.24.2.u1
Revenue - Disaggregation of Revenue - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Jun. 30, 2024
Jun. 30, 2023
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Including Assessed Tax $ 201,509 $ 229,986 $ 628,728 $ 696,763
Revenues 211,714 237,859 645,184 700,282
Natural Gas Sales [Member] | Transferred over Time [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Including Assessed Tax 183,876 215,108 594,715 666,502
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 3,066 3,201 6,071 6,000
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 1,328 502 1,930 3,256
Appliance Center Revenue [Member] | Transferred at Point in Time [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Including Assessed Tax 933 932 2,237 2,122
Other revenue [Member] | Transferred over Time [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Including Assessed Tax 12,306 10,243 23,775 18,883
Alternative revenue [Member]        
Disaggregation of Revenue [Line Items]        
Revenues 6,082 3,861 8,207 (4,491)
Leasing revenue [Member]        
Disaggregation of Revenue [Line Items]        
Operating leases 4,123 4,012 8,249 8,010
Northwest Natural Gas Company [Member]        
Disaggregation of Revenue [Line Items]        
Revenues 200,188 228,348 622,963 682,861
Operating leases 20 19 42 38
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Including Assessed Tax 189,983 220,475 606,507 679,342
Revenues 200,188 228,348 622,963 682,861
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Natural Gas Sales [Member] | Transferred over Time [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Including Assessed Tax 183,876 215,108 594,715 666,502
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 3,066 3,201 6,071 6,000
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 1,328 502 1,930 3,256
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 933 932 2,237 2,122
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 780 732 1,554 1,462
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Alternative revenue [Member]        
Disaggregation of Revenue [Line Items]        
Revenues 6,082 3,861 8,207 (4,491)
Northwest Natural Gas Company [Member] | Northwest Natural Gas Company [Member] | Leasing revenue [Member]        
Disaggregation of Revenue [Line Items]        
Operating leases 4,123 4,012 8,249 8,010
Operating Segments [Member] | Natural Gas Distribution [Member]        
Disaggregation of Revenue [Line Items]        
Revenues 194,862 223,714 612,726 671,484
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Including Assessed Tax 184,656 215,840 596,269 667,964
Revenues 194,861 223,713 612,725 671,483
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | Natural Gas Sales [Member] | Transferred over Time [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Including Assessed Tax 183,876 215,108 594,715 666,502
Operating Segments [Member] | Natural Gas Distribution [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 0 0 0 0
Operating Segments [Member] | Natural Gas Distribution [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 0 0 0 0
Operating Segments [Member] | Natural Gas Distribution [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 0 0 0 0
Operating Segments [Member] | Natural Gas Distribution [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 780 732 1,554 1,462
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | Alternative revenue [Member]        
Disaggregation of Revenue [Line Items]        
Revenues 6,082 3,861 8,207 (4,491)
Operating Segments [Member] | Natural Gas Distribution [Member] | Northwest Natural Gas Company [Member] | Leasing revenue [Member]        
Disaggregation of Revenue [Line Items]        
Operating leases 4,123 4,012 8,249 8,010
Operating Segments [Member] | Northwest Natural Gas Company [Member]        
Disaggregation of Revenue [Line Items]        
Revenues 200,188 228,348 622,963 682,861
Corporate, Non-Segment [Member] | Other Northwest Natural [Member]        
Disaggregation of Revenue [Line Items]        
Revenues 5,326 4,634 10,237 11,377
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax 5,327 4,635 10,238 11,378
Revenues 5,327 4,635 10,238 11,378
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | Natural Gas Sales [Member] | Transferred over Time [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax 0 0 0 0
Corporate, Non-Segment [Member] | Other Northwest Natural [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, Excluding Assessed Tax 3,066 3,201 6,071 6,000
Corporate, Non-Segment [Member] | Other Northwest Natural [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, Excluding Assessed Tax 1,328 502 1,930 3,256
Corporate, Non-Segment [Member] | Other Northwest Natural [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, Excluding Assessed Tax 933 932 2,237 2,122
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | Other revenue [Member] | Transferred over Time [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax 0 0 0 0
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | Alternative revenue [Member]        
Disaggregation of Revenue [Line Items]        
Revenues 0 0 0 0
Corporate, Non-Segment [Member] | Other Northwest Natural [Member] | Northwest Natural Gas Company [Member] | Leasing revenue [Member]        
Disaggregation of Revenue [Line Items]        
Operating leases 0 0 0 0
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax 11,526 9,511 22,221 17,421
Revenues 11,526 9,511 22,221 17,421
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member] | Natural Gas Sales [Member] | Transferred over Time [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax 0 0 0 0
Corporate, Non-Segment [Member] | Other Northwest Holdings [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 0
Corporate, Non-Segment [Member] | Other Northwest Holdings [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 0
Corporate, Non-Segment [Member] | Other Northwest Holdings [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 0
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member] | Other revenue [Member] | Transferred over Time [Member]        
Disaggregation of Revenue [Line Items]        
Revenue from Contract with Customer, Excluding Assessed Tax 11,526 9,511 22,221 17,421
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member] | Alternative revenue [Member]        
Disaggregation of Revenue [Line Items]        
Revenues 0 0 0 0
Corporate, Non-Segment [Member] | Other Northwest Holdings [Member] | Leasing revenue [Member]        
Disaggregation of Revenue [Line Items]        
Operating leases $ 0 $ 0 $ 0 $ 0