CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
OPERATING ACTIVITIES:
Net Income	$ 72,198	$ 120,468
Items not affecting cash:
Depreciation and depletion	90,047	86,600
Amortization of debt issuance costs, discount and deferred hedge gain	2,371	2,317
Stock-based compensation costs	4,195	3,597
Equity portion of allowance for funds used during construction	(2,318)	(2,318)
Loss (gain) on disposition of assets	3	(176)
Deferred income taxes	0	(16,547)
Changes in current assets and liabilities:
Accounts receivable	42,301	36,348
Inventories	(7,299)	(966)
Other current assets	570	(437)
Accounts payable	(7,319)	(19,683)
Accrued expenses	9,382	(20,781)
Regulatory assets	6,912	(13,106)
Regulatory liabilities	12,365	(23,652)
Other noncurrent assets	(3,694)	(3,059)
Other noncurrent liabilities	(495)	(3,992)
Cash Provided by Operating Activities	219,219	144,613
INVESTING ACTIVITIES:
Property, plant, and equipment additions	(176,482)	(147,027)
Investment in equity securities	(37)	0
Cash Used in Investing Activities	(176,519)	(147,027)
FINANCING ACTIVITIES:
Treasury stock activity	(2,076)	999
Dividends on common stock	(60,172)	(57,562)
Issuance of long-term debt	150,000	50,000
Line of credit (repayments) borrowings, net	(225,000)	7,000
Issuance of short-term borrowings	100,000	0
Financing costs	(1,109)	(875)
Cash Used in Financing Activities	(38,357)	(438)
Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	4,343	(2,852)
Cash, Cash Equivalents, and Restricted Cash, beginning of period	12,070	15,311
Cash, Cash Equivalents, and Restricted Cash, end of period	16,413	12,459
Cash paid during the period for:
Income taxes	55	68
Interest	42,115	42,100
Significant non-cash transactions:
Capital expenditures included in accounts payable	$ 13,835	$ 13,543