CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
OPERATING ACTIVITIES:
Net Income	$ 50,704	$ 72,806
Items not affecting cash:
Depreciation and depletion	45,265	45,584
Amortization of debt issue costs, discount and deferred hedge gain	1,167	1,157
Stock-based compensation costs	3,042	2,418
Equity portion of allowance for funds used during construction	(895)	(969)
Loss (gain) on disposition of assets	7	(164)
Deferred income taxes	170	708
Changes in current assets and liabilities:
Accounts receivable	11,494	(7,267)
Inventories	689	3,260
Other current assets	2,470	984
Accounts payable	(6,379)	3,954
Accrued expenses	35,810	27,781
Regulatory assets	9,845	(11,700)
Regulatory liabilities	8,259	(23,509)
Other noncurrent assets	(802)	(1,216)
Other noncurrent liabilities	(2,684)	(2,403)
Cash Provided by Operating Activities	158,162	111,424
INVESTING ACTIVITIES:
Property, plant, and equipment additions	(78,371)	(65,577)
Cash Used in Investing Activities	(78,371)	(65,577)
FINANCING ACTIVITIES:
Treasury stock activity	(2,492)	797
Dividends on common stock	(30,085)	(28,781)
Line of credit borrowings (repayments), net	6,000	(22,000)
Financing costs	(141)	(140)
Cash Used in Financing Activities	(26,718)	(50,124)
Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	53,073	(4,277)
Cash, Cash Equivalents, and Restricted Cash, beginning of period	12,070	15,311
Cash, Cash Equivalents, and Restricted Cash, end of period	65,143	11,034
Cash paid during the period for:
Income taxes	55	68
Interest	14,554	13,278
Significant non-cash transactions:
Capital expenditures included in accounts payable	$ 10,008	$ 12,643