Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Cash flows from operating activities
Net income (loss)	$ 126,281	$ (1,424,119)	$ 201,128
Adjustments to reconcile net income (loss) to net cash provided by operating activities-continuing operations
Loss (income) from discontinued operations	0	103,486	(53,362)
Depreciation of property, plant and equipment	260,024	261,701	254,990
Other amortization	38,895	31,832	27,316
Loss on sale of subsidiaries and equity-method investment and impairment loss on assets sold and held for sale	12,376	39,642	644
Deferred income tax expense (benefit)	(10,630)	(486,188)	9,352
Share-based compensation expense	3,426	3,591	6,776
Allowance for equity funds used during construction	(15,013)	(13,786)	(15,164)
Other	(6,359)	(13,790)	(2,989)
Changes in assets and liabilities
Decrease (increase) in accounts receivable and unbilled revenues, net	(51,351)	96,700	(71,643)
Decrease (increase) in fuel oil stock	(15,579)	49,361	43,388
Increase in materials and supplies	(14,458)	(4,177)	(34,887)
Increase in regulatory assets	(30,462)	(22,743)	(10,613)
Increase in regulatory liabilities	96,043	48,433	54,470
Increase in accounts, interest and dividends payable	7,032	6,862	34,290
Change in prepaid and accrued income taxes, tax credits and utility revenue taxes	(4,563)	(25,525)	(9,858)
Change in defined benefit pension and other postretirement benefit plans asset/liability	(8,788)	(9,358)	(8,215)
Increase in wildfire related claims	47,750	1,840,000	75,000
Change in other assets and liabilities	(43,551)	(53,812)	(57,255)
Net cash provided by operating activities-continuing operations	391,073	428,110	443,368
Net cash provided by operating activities-discontinued operations	0	59,371	108,103
Net cash provided by operating activities	391,073	487,481	551,471
Cash flows from investing activities
Capital expenditures	(341,202)	(344,251)	(442,727)
Proceeds from sale of subsidiaries	13,781	0	0
Other, net	5,246	10,330	6,558
Net cash used in investing activities-continuing operations	(322,175)	(333,921)	(436,169)
Net cash provided by investing activities-discontinued operations	0	592,239	178,770
Net cash used in investing activities	(322,175)	258,318	(257,399)
Cash flows from financing activities
Net decrease in short-term borrowings with original maturities of three months or less	0	0	(137,650)
Proceeds from issuance of short-term debt	0	50,000	65,000
Repayment of short-term debt	(50,000)	0	(100,000)
Proceeds from issuance of long-term debt	510,000	5,475	625,000
Repayment of long-term debt and funds transferred for repayment of long-term debt	(733,564)	(97,698)	(167,080)
Withheld shares for employee taxes on vested share-based compensation	(178)	(1,074)	(2,371)
Net proceeds from issuance of common stock	0	556,612	1,223
Common stock dividends	0	0	(73,957)
Preferred stock dividends of subsidiaries	(1,890)	(1,890)	(1,890)
Redemption of preferred stock of subsidiaries	(35,368)	0	0
Other	(20,004)	(13,867)	(5,133)
Net cash provided by (used in) financing activities-continuing operations	(331,004)	497,558	203,142
Net cash used in financing activities-discontinued operations	0	(342,853)	(7,567)
Net cash provided by (used in) financing activities	(331,004)	154,705	195,575
Net increase (decrease) in cash, cash equivalents and restricted cash, including cash from discontinued operations	(262,106)	900,504	489,647
Cash, cash equivalents and restricted cash from continuing operations, January 1	1,242,852	259,119	48,778
Cash, cash equivalents and restricted cash from discontinued operations, January 1	352,226	435,455	156,149
Cash, cash equivalents and restricted cash from discontinued operations, January 1	0
Cash, cash equivalents and restricted cash, including cash from discontinued operations, December 31	980,746	1,595,078	694,574
Less: Cash from discontinued operations	0	(352,226)	(435,455)
Cash, cash equivalents and restricted cash from continuing operations, December 31	980,746	1,242,852	259,119
Less: Restricted cash	(478,968)	(492,317)	(15,028)
Cash and cash equivalents from continuing operations, December 31	$ 501,778	$ 750,535	$ 244,091