CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
OPERATING ACTIVITIES:
Net Income	$ 72,806	$ 58,499
Items not affecting cash:
Depreciation and depletion	45,584	43,755
Amortization of debt issue costs, discount and deferred hedge gain	1,157	1,171
Stock-based compensation costs	2,418	2,496
Equity portion of allowance for funds used during construction	(969)	(618)
(Gain) loss on disposition of assets	(164)	15
Deferred income taxes	708	2,143
Changes in current assets and liabilities:
Accounts receivable	(7,267)	12,012
Inventories	3,260	8,718
Other current assets	984	3,258
Accounts payable	3,954	(21,605)
Accrued expenses	27,781	41,802
Regulatory assets	(11,700)	13,208
Regulatory liabilities	(23,509)	2,205
Other noncurrent assets	(1,216)	(1,505)
Other noncurrent liabilities	(2,403)	7,474
Cash Provided by Operating Activities	111,424	173,028
INVESTING ACTIVITIES:
Property, plant, and equipment additions	(65,577)	(52,005)
Cash Used in Investing Activities	(65,577)	(52,005)
FINANCING ACTIVITIES:
Treasury stock activity	797	1,574
Dividends on common stock	(28,781)	(26,945)
Line of credit repayments, net	(22,000)	0
Line of credit borrowings	0	578,000
Line of credit repayments	0	(355,000)
Repayments of short-term borrowings, net	0	(319,556)
Financing costs	(140)	(225)
Cash Used in Financing Activities	(50,124)	(122,152)
Decrease in Cash, Cash Equivalents, and Restricted Cash	(4,277)	(1,129)
Cash, Cash Equivalents, and Restricted Cash, beginning of period	15,311	12,029
Cash, Cash Equivalents, and Restricted Cash, end of period	11,034	10,900
Cash paid during the period for:
Income taxes	68	55
Interest	13,278	12,172
Significant non-cash transactions:
Capital expenditures included in accounts payable	$ 12,643	$ 7,135