v3.26.1
REPORTABLE SEGMENT DATA - RECONCILIATION OF SEGMENT INCOME TO CONSOLIDATED (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Dec. 31, 2025
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments $ 349,180     $ 298,946     $ 1,893,435 $ 1,700,334
Corporate and other 257,985     234,836     1,340,234 1,162,987
Operation and maintenance 105,574     100,133     304,751 299,806
Regulatory rider expenses 10,434     10,979     103,038 81,956
Depreciation and amortization 53,545     47,000     153,250 140,296
Gain on sale of assets 0     (545)     0 (56,092)
Interest expense, net of capitalized interest 35,199     31,694     105,850 98,112
Income tax provision (benefit) 3,353     (5,142)     103,754 93,835
Equity in earnings of affiliates 1,577     1,523     6,141 4,375
Total net income (loss) 9,689 $ 218,912 $ 122,490 (15,051) $ 204,287 $ 131,319 351,091 320,555
ES                
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments 4,900     4,900     14,800 14,800
Corporate and other                
Segment Reporting [Line Items]                
Corporate and other 17,545     15,909     48,034 45,880
Total net income (loss) 802     812     92 1,250
Operating Segments                
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments 331,427     282,799     1,844,718 1,653,532
Natural gas purchases 148,365     143,088     822,203 768,445
Operation and maintenance 89,538     85,694     259,773 256,381
Regulatory rider expenses 10,434     10,979     103,038 81,956
Depreciation and amortization 53,284     46,598     152,424 139,467
Gain on sale of assets       (545)       (56,092)
Interest income 2,669     3,278     8,244 9,500
Other segment income (expense) 13,799     8,676     40,139 33,039
Interest expense, net of capitalized interest 35,630     31,447     108,203 97,404
Income tax provision (benefit) 3,004     (5,499)     101,705 93,157
Equity in earnings of affiliates 1,039     908     4,561 3,030
Net income (loss) attributable to reportable segments 8,887     (15,863)     350,999 319,305
Operating Segments | NJNG                
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments 200,869     204,790     1,251,692 1,156,558
Corporate and other 171,766     167,902     1,120,971 973,112
Natural gas purchases 65,875     74,941     513,166 480,244
Operation and maintenance 64,682     61,849     179,385 175,200
Regulatory rider expenses 10,434     10,979     103,038 81,956
Depreciation and amortization 40,385     35,987     114,854 103,784
Gain on sale of assets       0       0
Interest income 1,098     687     2,471 1,934
Other segment income (expense) 6,413     6,793     18,539 18,206
Interest expense, net of capitalized interest 19,029     16,184     57,508 50,897
Income tax provision (benefit) 2,126     2,489     67,035 63,980
Equity in earnings of affiliates 0     0     0 0
Net income (loss) attributable to reportable segments 6,087     10,079     238,429 221,518
Operating Segments | CEV                
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments 19,178     12,030     60,870 46,403
Corporate and other 19,024     11,851     37,259 28,406
Natural gas purchases 0     0     0 0
Operation and maintenance 10,358     11,156     30,247 32,426
Regulatory rider expenses 0     0     0 0
Depreciation and amortization 7,664     5,772     21,817 17,701
Gain on sale of assets       (545)       (56,092)
Interest income 0     280     31 530
Other segment income (expense) 7,346     1,777     21,480 14,351
Interest expense, net of capitalized interest 8,845     6,629     25,383 18,940
Income tax provision (benefit) (31)     (2,068)     879 10,994
Equity in earnings of affiliates 0     0     0 0
Net income (loss) attributable to reportable segments (312)     (6,857)     4,055 37,315
Operating Segments | ES                
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments 79,962     38,850     443,224 371,548
Corporate and other 18,024     11,807     44,355 35,644
Natural gas purchases 82,091     67,781     307,803 287,496
Operation and maintenance 3,059     1,279     16,014 14,352
Regulatory rider expenses 0     0     0 0
Depreciation and amortization 41     30     125 139
Gain on sale of assets       0       0
Interest income 20     36     80 109
Other segment income (expense) 170     322     511 1,025
Interest expense, net of capitalized interest 2,373     2,893     8,915 10,040
Income tax provision (benefit) (1,762)     (7,792)     26,276 14,088
Equity in earnings of affiliates 0     0     0 0
Net income (loss) attributable to reportable segments (5,650)     (24,983)     84,682 46,567
Operating Segments | S&T                
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments 31,418     27,129     88,932 79,023
Corporate and other 31,418     27,129     88,932 79,023
Natural gas purchases 399     366     1,234 705
Operation and maintenance 11,439     11,410     34,127 34,403
Regulatory rider expenses 0     0     0 0
Depreciation and amortization 5,194     4,809     15,628 17,843
Gain on sale of assets       0       0
Interest income 1,551     2,275     5,662 6,927
Other segment income (expense) (130)     (216)     (391) (543)
Interest expense, net of capitalized interest 5,383     5,741     16,397 17,527
Income tax provision (benefit) 2,671     1,872     7,515 4,095
Equity in earnings of affiliates 1,039     908     4,561 3,030
Net income (loss) attributable to reportable segments 8,762     5,898     23,833 13,905
Intersegment Eliminations                
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments 208     238     683 922
Intersegment Eliminations | NJNG                
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments 238     238     713 881
Intersegment Eliminations | CEV                
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments 0     0     0 0
Intersegment Eliminations | ES                
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments 0     0     0 0
Intersegment Eliminations | S&T                
Segment Reporting [Line Items]                
Operating revenues attributable to reportable segments $ (30)     $ 0     $ (30) $ 41