CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating Activities:
Net income	$ 83,018	$ 82,091
Non-cash items included in net income:
Depreciation and amortization	125,445	111,487
Deferred income tax provision and investment tax credits	(12,930)	11,085
Power and natural gas cost deferrals, net	(19,326)	(21,826)
Amortization of debt expense	1,042	1,571
Stock-based compensation expense	3,646	2,280
Equity-related AFUDC	(3,614)	(3,346)
Pension and other postretirement benefit expense	10,557	14,793
Other regulatory assets and liabilities and deferred debits and credits	5,559	4,008
Change in decoupling regulatory deferral	22,550	2,203
Realized and unrealized gain on assets and investments	(13,144)	(9,085)
Other	4,749	(332)
Contributions to defined benefit pension plan	(28,000)	(28,000)
Cash paid for settlement of interest rate swap agreements	(17,035)
Changes in certain current assets and liabilities:
Accounts and notes receivable	33,206	26,284
Materials and supplies, fuel stock and stored natural gas	(21,058)	(15,328)
Collateral posted for derivative instruments	18,131	(24,102)
Income taxes receivable	(168)	23,869
Other current assets	(1,294)	2,505
Accounts payable	(13,530)	8,111
Other current liabilities	28,137	1,795
Net cash provided by operating activities	205,941	190,063
Investing Activities:
Utility property capital expenditures (excluding equity-related AFUDC)	(210,646)	(213,827)
Equity and property investments	(7,765)	(5,650)
Proceeds from sale of investments		6,806
Other	(1,008)	1,832
Net cash used in investing activities	(219,419)	(210,839)
Financing Activities:
Net increase (decrease) in short-term borrowings	(126,000)	93,000
Proceeds from issuance of long-term debt	399,856
Maturity of long-term debt and finance leases	(251,543)	(1,491)
Issuance of common stock, net of issuance costs	60,765	15,689
Cash dividends paid	(64,077)	(58,693)
Other	(6,072)	(2,898)
Net cash provided by financing activities	12,929	45,607
Net increase (decrease) in cash and cash equivalents	(549)	24,831
Cash and cash equivalents at beginning of period	22,168	14,196
Cash and cash equivalents at end of period	$ 21,619	$ 39,027