Unaudited Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATIONS:
Net income	$ 38,784	$ 35,983
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	63,089	60,708
Amortization of redemption premiums and expense on debt	998	1,100
Deferred income taxes and investment tax credit adjustments - net	922	2,467
Allowance for equity funds used during construction	(1,374)	(857)
Change in certain assets and liabilities:
Accounts receivable	4,458	4,655
Inventories	12,568	(8,265)
Increase (Decrease) in Accounts Payable	3,610	(7,940)
Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities	(6,271)	(2,514)
Accrued real estate and personal property taxes	20,419	15,382
Accrued interest	11,181	2,599
Pension and other postretirement benefit expenses	46	(1,726)
Short-term and long-term regulatory assets and liabilities	(14,905)	(3,226)
Increase (Decrease) in Prepaid Expense and Other Assets	23,599	5,488
Other - net	(2,038)	4,698
Net cash provided by operating activities	107,888	97,576
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(62,792)	(54,490)
Project development costs	(386)	(751)
Cost of removal and regulatory recoverable ARO payments	(6,589)	(7,962)
Net cash used in investing activities	(69,767)	(63,203)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayments of Lines of Credit	(45,000)	0
Distributions to Shareholders	30,073	26,631
Payments of Deferred Finance Costs	(270)	0
Proceeds from Lines of Credit	60,000	0
Preferred dividends of subsidiary	(803)	(803)
Net cash used in financing activities	(16,146)	(27,434)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	21,975	6,939
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	48,597	55,491
Supplemental disclosures of cash flow information:
Capital Expenditures Incurred but Not yet Paid	46,060	28,184
Cash paid during the period for:
Interest (net of amount capitalized)	18,512	26,438
Net income	38,784	35,983
Depreciation and amortization	63,089	60,708
Amortization of redemption premiums and expense on debt	998	1,100
Deferred income taxes and investment tax credit adjustments - net	922	2,467
Increase (Decrease) in Allowance for Equity Funds Used During Construction	1,374	857
Increase (Decrease) in Regulatory Assets and Liabilities	14,905	3,226
Increase (Decrease) in Prepaid Expense and Other Assets	23,599	5,488
Other - net	(2,038)	4,698
Net Cash Provided by (Used in) Operating Activities	107,888	97,576
Increase (Decrease) in Accounts Receivable	(4,458)	(4,655)
Increase (Decrease) in Inventories	(12,568)	8,265
Increase (Decrease) in Accounts Payable	3,610	(7,940)
Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities	(6,271)	(2,514)
Increase (Decrease) in Property and Other Taxes Payable	20,419	15,382
Accrued interest	11,181	2,599
Pension and other postretirement benefit expenses	$ 46	$ (1,726)