STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating activities
Net income	$ 173,091	$ 128,198
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	150,403	144,664
Demand side management program amortization	1,255	1,255
Deferred income taxes	14,395	101,388
Amortization of investment tax credits	(39)	(99)
Allowance for equity funds used during construction	(11,637)	(6,457)
Net derivative losses	47	47
Other, net	(5)	9
Changes in operating assets and liabilities:
Accounts receivable	(25,096)	(25,134)
Accrued unbilled revenues	9,648	(13,682)
Inventories	7,032	(2,845)
Prepayments and other	641	19,361
Accounts payable	(935)	7,817
Net regulatory assets and liabilities	58,832	24,856
Other current liabilities	12,972	19,748
Pension and other employee benefit obligations	(7,907)	(21,638)
Change in other noncurrent assets	3,546	(1,697)
Change in other noncurrent liabilities	(235)	(18,690)
Net cash provided by operating activities	386,008	357,101
Investing activities
Utility capital/construction expenditures	(621,641)	(400,957)
Allowance for equity funds used during construction	11,637	6,457
Investments in utility money pool arrangement	46,000	0
Repayments from utility money pool arrangement	111,000	0
Payments for (Proceeds from) Other Investing Activities	0	(493)
Net cash used in investing activities	(545,004)	(394,993)
Financing activities
Proceeds from short-term borrowings, net	35,000	(50,000)
Proceeds from issuance of long-term debt, net	0	442,651
Borrowings under utility money pool arrangement	446,000	323,000
Repayments under utility money pool arrangement	(423,000)	(323,000)
Capital contributions from parent	181,484	45,000
Repayment of long-term debt	0	(271,613)
Dividends paid to parent	(90,705)	(82,599)
Other, net	(31)	0
Net cash provided by financing activities	148,748	83,439
Net change in cash and cash equivalents	(10,248)	45,547
Cash and cash equivalents at beginning of period	10,871	844
Cash and cash equivalents at end of period	623	46,391
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(57,924)	(58,581)
Cash (paid) received for income taxes, net	(15,251)	37,899
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 54,601	$ 40,861