Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net margin	$ 69,951	$ 72,244
Adjustments to reconcile net margin to net cash provided by operating activities:
Depreciation and amortization, including nuclear fuel	323,256	333,245
Accretion cost	48,969	41,410
Amortization of deferred gains	(1,341)	(1,341)
Allowance for equity funds used during construction	(530)	(460)
Deferred outage costs	(30,995)	(26,712)
(Gain) loss on sale of investments	(6,422)	21,077
Regulatory deferral of costs associated with nuclear decommissioning	(15,194)	(45,229)
Other	(508)	2,352
Change in operating assets and liabilities:
Receivables	2,225	(84,191)
Inventories	(19,625)	(10,312)
Prepayments and other current assets	(2,290)	8,859
Accounts payable	(70,878)	29,464
Accrued interest	10,805	(6,565)
Accrued taxes	(3,261)	51,394
Other current liabilities	(60,185)	47,369
Rate management program (disbursements) collections	(40,898)	16,904
Other	(53,747)	(12,847)
Total adjustments	79,381	364,417
Net cash provided by operating activities	149,332	436,661
Cash flows from investing activities:
Property additions	(719,492)	(872,551)
Plant acquisition	(16,743)	0
Activity in nuclear decommissioning trust fund—Purchases	(359,461)	(201,721)
Activity in nuclear decommissioning trust fund—Proceeds	351,627	196,136
Decrease in restricted investments	74,031	246,427
Activity in long-term and short-term investments—Purchases	(198,079)	(144,843)
Activity in other long-term investments—Proceeds	149,928	103,024
Other	19,239	5,569
Net cash used in investing activities	(698,950)	(667,959)
Cash flows from financing activities:
Long-term debt proceeds	79,284	803,032
Long-term debt payments	(244,621)	(365,104)
Increase (decrease) in short-term borrowings, net	533,950	(171,310)
Other	46,561	23,958
Net cash provided by financing activities	415,174	290,576
Net (decrease) increase in cash, cash equivalents and restricted cash	(134,444)	59,278
Cash, cash equivalents and restricted cash at beginning of period	625,781	581,150
Cash, cash equivalents and restricted cash at end of period	491,337	640,428
Cash paid for—
Interest (net of amounts capitalized)	170,189	150,208
Supplemental disclosure of non-cash investing and financing activities:
Change in asset retirement obligations	73,739	66,716
Accrued property additions at end of period	$ 22,266	$ 45,926