CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
OPERATING ACTIVITIES:
Net Income	$ 101,664	$ 142,138
Items not affecting cash:
Depreciation and depletion	134,336	129,766
Amortization of debt issuance costs, discount and deferred hedge gain	3,604	3,482
Stock-based compensation costs	5,347	4,778
Equity portion of allowance for funds used during construction	(4,503)	(4,118)
Gain on disposition of assets	(26)	(176)
Deferred income taxes	(3,759)	(16,350)
Changes in current assets and liabilities:
Accounts receivable	34,290	36,000
Inventories	(15,130)	(4,353)
Other current assets	(4,194)	(3,332)
Accounts payable	(4,181)	(13,942)
Accrued expenses	67,553	24,945
Regulatory assets	7,372	(17,662)
Regulatory liabilities	13,433	(19,265)
Other noncurrent assets	(6,225)	(5,366)
Other noncurrent liabilities	(7,066)	(2,684)
Cash Provided by Operating Activities	322,515	253,861
INVESTING ACTIVITIES:
Property, plant, and equipment additions	(282,987)	(242,874)
Investment in equity securities	(42)	0
Cash Used in Investing Activities	(283,029)	(242,874)
FINANCING ACTIVITIES:
Treasury stock activity	(1,723)	1,220
Dividends on common stock	(90,260)	(86,343)
Issuance of long-term debt	150,000	150,000
Line of credit repayments, net	(193,000)	(76,000)
Issuance of short-term borrowings	100,000	0
Financing costs	(2,564)	(1,074)
Cash Used in Financing Activities	(37,547)	(12,197)
Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	1,939	(1,210)
Cash, Cash Equivalents, and Restricted Cash, beginning of period	12,070	15,311
Cash, Cash Equivalents, and Restricted Cash, end of period	14,009	14,101
Cash paid during the period for:
Income taxes	100	68
Interest	55,220	55,515
Significant non-cash transactions:
Capital expenditures included in accounts payable	$ 15,986	$ 15,508