STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Document Fiscal Year Focus	2020
Operating activities
Net income	$ 138,081	$ 135,587
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	142,898	134,260
Deferred income taxes	11,175	9,099
Share-based compensation expense	7,439	7,153
Provision for doubtful accounts	8,836	4,600
Changes in assets and liabilities:
Accounts receivable	144,399	160,053
Materials and supplies	240	(12,455)
Natural gas in storage	(1,118)	(11,155)
Increase (Decrease) in Other Regulatory Assets	(29,019)	(38,101)
Accounts payable	(50,848)	(113,665)
Accrued taxes other than income	9,776	(435)
Customer deposits	(2,668)	(3,652)
Regulatory assets and liabilities	(24,478)	20,196
Other assets and liabilities	(29,384)	(2,942)
Cash provided by operating activities	325,329	288,543
Investing activities
Capital expenditures	(348,915)	(305,797)
Other	(1,379)	(4,056)
Proceeds from Sale of Other Assets, Investing Activities	2,482	1,036
Cash used in investing activities	(347,812)	(308,817)
Financing activities
Repayments of notes payable, net	(208,500)	95,500
Proceeds from Issuance of Senior Long-term Debt	297,750	0
Payments of Debt Issuance Costs	(2,885)	0
Proceeds from Issuance of Common Stock	16,325	2,536
Dividends paid	(85,698)	(79,055)
Tax withholdings related to net share settlements of stock compensation	(6,178)	(7,468)
Cash used in financing activities	10,814	11,513
Change in cash and cash equivalents	(11,669)	(8,761)
Cash and cash equivalents at beginning of period	17,853	21,323
Cash and cash equivalents at end of period	$ 6,184	$ 12,562