v3.25.2
SEGMENT INFORMATION - Summary of Segment Information and Segmented Total Assets (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2024
Mar. 31, 2024
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Segment Reporting Information [Line Items]              
Operating Revenues $ 2,838,068   $ 2,533,522   $ 6,956,423 $ 5,866,097  
Depreciation and Amortization (494,700)   (240,400)   (1,329,800) (578,000)  
Operations, Excluding Storm Costs      
Corporate Shared Services      
Storm Costs      
Employee Benefits      
Uncollectible Expense      
Total Operations and Maintenance (467,557)   (464,424)   (955,008) (927,388)  
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (1,212,800)   (1,226,200)   (3,082,200) (2,912,200)  
Operating Income 663,049   602,498   1,589,443 1,448,470  
Interest Expense (293,193)   (271,316)   (594,042) (522,064)  
Interest Income 30,800   37,100   64,800 67,100  
Other Income, Net 64,600   78,200   122,900 139,200  
Income Tax (Expense)/Benefit (110,611)   (109,246)   (275,831) (271,772)  
Income Tax Expense     (109,300)     (271,700)  
Net Income 354,608 $ 552,668 337,221 $ 523,728 907,276 860,949  
Net Income           861,000  
Net Income Attributable to Noncontrolling Interests (1,880)   (1,880)   (3,759) (3,759)  
Net Income Attributable to Common Shareholders 352,728   335,341   903,517 857,190  
Cash Flows Used for Investments in Plant         2,049,400 2,220,900  
Assets 60,956,100       60,956,100   $ 59,594,529
Other              
Segment Reporting Information [Line Items]              
Operating Revenues 405,800   395,200   844,900 838,800  
Depreciation and Amortization (53,400)   (48,500)   (104,100) (94,100)  
Operations, Excluding Storm Costs      
Corporate Shared Services      
Storm Costs      
Employee Benefits      
Uncollectible Expense      
Total Operations and Maintenance (313,300)   (312,300)   (662,400) (660,900)  
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (1,000)   (1,900)   (2,400) (2,800)  
Operating Income 38,100   32,500   76,000 81,000  
Interest Expense (176,900)   (161,000)   (355,300) (307,200)  
Interest Income 43,200   58,600   86,600 113,300  
Other Income, Net 433,900   414,900   1,059,600 982,900  
Income Tax (Expense)/Benefit 23,700       57,100    
Income Tax Expense     6,800     22,300  
Net Income 362,000   351,800   924,000    
Net Income           892,300  
Net Income Attributable to Noncontrolling Interests 0   0   0 0  
Net Income Attributable to Common Shareholders 362,000   351,800   924,000 892,300  
Cash Flows Used for Investments in Plant         119,900 125,600  
Assets 28,405,200       28,405,200   29,041,100
Eliminations              
Segment Reporting Information [Line Items]              
Operating Revenues (824,700)   (813,100)   (1,662,500) (1,649,800)  
Depreciation and Amortization 3,600   2,700   6,300 5,200  
Operations, Excluding Storm Costs      
Corporate Shared Services      
Storm Costs      
Employee Benefits      
Uncollectible Expense      
Total Operations and Maintenance 409,700   398,500   850,700 844,200  
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency 411,400   411,900   805,500 800,400  
Operating Income 0   0   0 0  
Interest Expense 43,200   58,600   86,600 113,300  
Interest Income (43,200)   (58,600)   (86,600) (113,200)  
Other Income, Net (428,500)   (390,300)   (1,049,600) (949,800)  
Income Tax (Expense)/Benefit 0       0    
Income Tax Expense     0     0  
Net Income (428,500)   (390,300)   (1,049,600)    
Net Income           (949,700)  
Net Income Attributable to Noncontrolling Interests 0   0   0 0  
Net Income Attributable to Common Shareholders (428,500)   (390,300)   (1,049,600) (949,700)  
Cash Flows Used for Investments in Plant         0 0  
Assets (29,762,600)       (29,762,600)   (29,851,900)
Electric Distribution | Operating Segments              
Segment Reporting Information [Line Items]              
Operating Revenues 2,166,400   1,966,300   4,944,100 4,228,000  
Depreciation and Amortization (265,800)   (34,900)   (830,600) (144,600)  
Operations, Excluding Storm Costs (96,500)   (109,900)   (198,100) (221,600)  
Corporate Shared Services (105,700)   (104,900)   (222,000) (217,400)  
Storm Costs (21,900)   (17,200)   (41,800) (43,600)  
Employee Benefits (47,300)   (40,700)   (95,800) (85,500)  
Uncollectible Expense (41,100)   (39,600)   (84,800) (74,900)  
Other (39,600)   (38,100)   (67,300) (55,500)  
Total Operations and Maintenance (352,100)   (350,400)   (709,800) (698,500)  
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (1,307,900)   (1,363,200)   (2,888,400) (2,920,200)  
Operating Income 240,600   217,800   515,300 464,700  
Interest Expense (95,400)   (90,900)   (186,500) (173,400)  
Interest Income 24,800   31,900   52,100 56,300  
Other Income, Net 39,300   35,100   74,600 67,200  
Income Tax (Expense)/Benefit (46,600)       (103,200)    
Income Tax Expense     (43,000)     (94,600)  
Net Income 162,700   150,900   352,300    
Net Income           320,200  
Net Income Attributable to Noncontrolling Interests (1,200)   (1,200)   (2,300) (2,300)  
Net Income Attributable to Common Shareholders 161,500   149,700   350,000 317,900  
Cash Flows Used for Investments in Plant         983,200 883,600  
Assets 32,973,200       32,973,200   32,031,900
Natural Gas Distribution | Operating Segments              
Segment Reporting Information [Line Items]              
Operating Revenues 460,800   393,500   1,602,100 1,299,500  
Depreciation and Amortization (57,700)   (50,100)   (162,100) (133,200)  
Operations, Excluding Storm Costs (40,800)   (39,400)   (87,100) (82,100)  
Corporate Shared Services (28,000)   (26,100)   (58,300) (53,100)  
Storm Costs 0   0   0 0  
Employee Benefits (17,200)   (15,900)   (35,700) (33,200)  
Uncollectible Expense (13,400)   (6,400)   (43,400) (22,500)  
Other (5,100)   (8,200)   (2,900) (11,200)  
Total Operations and Maintenance (104,500)   (96,000)   (227,400) (202,100)  
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (235,400)   (199,200)   (840,700) (647,700)  
Operating Income 63,200   48,200   371,900 316,500  
Interest Expense (28,100)   (22,300)   (56,500) (46,800)  
Interest Income 5,800   5,100   12,400 10,600  
Other Income, Net 8,900   5,800   14,500 10,400  
Income Tax (Expense)/Benefit (14,500)       (88,600)    
Income Tax Expense     (9,700)     (73,100)  
Net Income 35,300   27,100   253,700    
Net Income           217,600  
Net Income Attributable to Noncontrolling Interests 0   0   0 0  
Net Income Attributable to Common Shareholders 35,300   27,100   253,700 217,600  
Cash Flows Used for Investments in Plant         372,500 467,900  
Assets 10,092,500       10,092,500   9,786,700
Electric Transmission | Operating Segments              
Segment Reporting Information [Line Items]              
Operating Revenues 568,700   534,100   1,116,500 1,041,900  
Depreciation and Amortization (109,600)   (98,800)   (216,300) (199,800)  
Operations, Excluding Storm Costs (37,000)   (34,400)   (68,500) (67,400)  
Corporate Shared Services (16,900)   (16,800)   (38,700) (36,300)  
Storm Costs 0   0   0 0  
Employee Benefits (11,900)   (10,300)   (23,600) (22,500)  
Uncollectible Expense 0   0   0 0  
Other (18,300)   (18,100)   (29,200) (33,800)  
Total Operations and Maintenance (84,100)   (79,600)   (160,000) (160,000)  
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (73,200)   (67,500)   (142,800) (129,000)  
Operating Income 301,800   288,200   597,400 553,100  
Interest Expense (28,300)   (46,000)   (66,800) (86,900)  
Interest Income 200   100   300 100  
Other Income, Net 9,600   12,100   21,600 26,200  
Income Tax (Expense)/Benefit (74,600)       (143,500)    
Income Tax Expense     (64,700)     (125,300)  
Net Income 208,700   189,700   409,000    
Net Income           367,200  
Net Income Attributable to Noncontrolling Interests (700)   (700)   (1,500) (1,500)  
Net Income Attributable to Common Shareholders 208,000   189,000   407,500 365,700  
Cash Flows Used for Investments in Plant         505,700 668,100  
Assets 16,679,400       16,679,400   16,070,900
Water Distribution | Operating Segments              
Segment Reporting Information [Line Items]              
Operating Revenues 61,100   57,500   111,300 107,700  
Depreciation and Amortization (11,800)   (10,800)   (23,000) (11,500)  
Operations, Excluding Storm Costs      
Corporate Shared Services      
Storm Costs      
Employee Benefits      
Uncollectible Expense      
Total Operations and Maintenance (23,300)   (24,600)   (46,100) (50,100)  
Purchased Power, Purchased Natural Gas and Transmission, Other Taxes and Energy Efficiency (6,700)   (6,300)   (13,400) (12,900)  
Operating Income 19,300   15,800   28,800 33,200  
Interest Expense (7,700)   (9,700)   (15,500) (21,100)  
Interest Income 0   0   0 0  
Other Income, Net 1,400   600   2,200 2,300  
Income Tax (Expense)/Benefit 1,400       2,400    
Income Tax Expense     1,300     (1,000)  
Net Income 14,400   8,000   17,900    
Net Income           13,400  
Net Income Attributable to Noncontrolling Interests 0   0   0 0  
Net Income Attributable to Common Shareholders 14,400   $ 8,000   17,900 13,400  
Cash Flows Used for Investments in Plant         68,100 $ 75,700  
Assets $ 2,568,400       $ 2,568,400   $ 2,515,800