Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Flows from Operating Activities:
Net Income	$ 88,565	$ 157,042	$ 76,917
(Income) Loss from Discontinued Operations - Net of taxes	(51)	255	272
Income from Continuing Operations	88,514	157,297	77,189
Adjustments to Reconcile Income from Continuing Operations to Net Cash Provided by Operating Activities:
Net Gain on Sales of Assets	0	(2,578)	(3,133)
Step Acquisition Gain	0	(1,971)	0
Payment of Swap Termination	0	(8,173)	0
Gain on Insurance Proceeds	0	0	(794)
Impairment Charges	0	0	10,745
Impairment on Investments in Equity Method Investees	102,872	0	0
Gain from Tax Settlement	(10,960)	0	0
Depreciation and Amortization	211,652	170,647	133,385
Net Unrealized (Gain) Loss on Derivatives - Energy Related	(5,567)	(385)	11,748
Unrealized (Gain) Loss on Derivatives - Other	0	(4,760)	2,798
Provision for Uncollectibles	10,159	9,558	10,432
CIP Receivable/Payable	3,237	(27,807)	922
Deferred Gas Costs and Energy Related Derivatives - Net of Recoveries	(29,000)	44,450	16,654
Stock-Based Compensation Expense	5,966	5,797	5,209
Deferred and Noncurrent Income Taxes - Net	47,342	21,841	21,543
Environmental Remediation Costs - Net of Recoveries	(34,057)	(19,325)	(49,180)
Gas Plant Cost of Removal	(13,847)	(16,777)	(18,823)
Dividends Received from Equity Method Investments	2,849	1,714	1,770
Income from Equity Method Investments	(5,467)	(8,294)	(7,314)
Societal Benefit Costs Regulatory Asset and Liabilities	(21,915)	(23,068)	(24,503)
Excess Deferred Income Tax	(21,901)	(14,668)	(8,505)
Changes in:
Accounts Receivable	(85,911)	(48,576)	92,614
Accounts Payable and Other Accrued Liabilities	80,715	49,981	(137,717)
Other Assets and Liabilities	(51,570)	26,733	(13,988)
Cash Flows from Discontinued Operations	2	3	0
CASH USED IN OPERATING ACTIVITIES	273,113	311,639	121,052
Cash Flows from Investing Activities:
Capital Expenditures	(532,026)	(486,451)	(504,212)
Acquisition-related Working Capital Settlement	(267)	0	15,600
Cash Paid for Acquisitions, Net of Cash Acquired	0	(21,613)	(3,952)
Proceeds from Business Dispositions and Sale of Property, Plant and Equipment	0	119,948	26,938
Investment in Contract Receivables	(22,215)	(24,449)	(15,718)
Proceeds from Contract Receivables	13,969	12,904	10,301
Proceeds from Company-Owned Life Insurance	0	0	1,694
Investment in Subsidiary, Net of Cash Acquired	(44,356)	(79,181)	0
Investment in Affiliates	(14,039)	(12,139)	(4,866)
Net Advances on Notes Receivable - Affiliates	(46,563)	(19,301)	(3,433)
Net Repayment of Notes Receivable - Affiliates	0	2,531	0
Net Cash Used in Investing Activities	(645,497)	(507,751)	(477,648)
Cash Flows from Financing Activities:
Net (Repayments of) Borrowings from Short-Term Credit Facilities	(262,400)	(252,300)	578,200
Proceeds from Issuance of Long-Term Debt	460,000	1,050,000	429,657
Payments for Issuance of Long-Term Debt	(17,632)	(8,191)	(2,744)
Principal Repayments of Long-Term Debt	(117,909)	(667,909)	(733,909)
Dividends on Common Stock	(133,336)	(114,643)	(106,938)
Proceeds from Sale of Common Stock	429,772	200,000	189,032
Payments for the Issuance of Common Stock	(2,322)	(2,409)	0
Capital Contributions of Noncontrolling Interests in Subsidiary	3,820	6,037	0
Other	0	(1,023)	0
Net Cash Provided by Financing Activities	359,993	209,562	353,298
Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash	(12,391)	13,450	(3,298)
Cash, Cash Equivalents and Restricted Cash at Beginning of Year	41,831	28,381	31,679
Cash, Cash Equivalents and Restricted Cash at End of Year	29,440	41,831	28,381
Cash paid (received) during the year for:
Interest (Net of Amounts Capitalized)	122,070	108,901	114,015
Income Taxes (Net of Refunds)	(301)	(4,336)	(10,639)
Supplemental Disclosures of Non-Cash Investing Activities
Capital Expenditures acquired on account but unpaid as of year-end	$ 36,389	$ 37,616	$ 54,321