CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Operating Activities:
Net income	$ 72,329	$ 83,018
Non-cash items included in net income:
Depreciation and amortization	131,367	125,445
Deferred income tax provision and investment tax credits	(20,565)	(12,930)
Power and natural gas cost deferrals, net	(31,559)	(19,326)
Amortization of debt expense	1,980	1,042
Stock-based compensation expense	5,460	3,646
Equity-related AFUDC	(3,172)	(3,614)
Pension and other postretirement benefit expense	6,693	10,557
Other regulatory assets and liabilities	(31,997)	9,291
Other deferred debits and credits	32,351	(3,732)
Change in decoupling regulatory deferral	14,383	22,550
Realized and unrealized loss (gain) on assets and investments	2,752	(13,144)
Other	(2,436)	4,749
Contributions to defined benefit pension plan	(6,666)	(28,000)
Cash paid for settlement of interest rate swap agreements	(409)	(17,035)
Cash received for settlement of interest rate swap agreements	7,869
Changes in certain current assets and liabilities:
Accounts and notes receivable	111,428	33,206
Inventory	(8,131)	(21,058)
Collateral posted for derivative instruments	116,602	18,131
Income taxes receivable	7,476	(168)
Other current assets	(20,228)	(1,294)
Accounts payable	(96,080)	(13,530)
Other current liabilities	(19,886)	28,137
Net cash provided by operating activities	269,561	205,941
Investing Activities:
Utility property capital expenditures (excluding equity-related AFUDC)	(226,746)	(210,646)
Issuance of notes receivable	(1,500)	(1,772)
Equity and property investments	(6,481)	(7,765)
Other	652	764
Net cash used in investing activities	(234,075)	(219,419)
Financing Activities:
Net decrease in short-term borrowings	(260,000)	(126,000)
Proceeds from issuance of long-term debt	250,000	399,856
Maturity of long-term debt and finance leases	(8,118)	(251,543)
Issuance of common stock, net of issuance costs	59,525	60,765
Cash dividends paid	(69,942)	(64,077)
Other	(4,675)	(6,072)
Net cash provided by (used in) financing activities	(33,210)	12,929
Net increase (decrease) in cash and cash equivalents	2,276	(549)
Cash and cash equivalents at beginning of period	13,428	22,168
Cash and cash equivalents at end of period	$ 15,704	$ 21,619