STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities
Net income	$ 123,080	$ 104,638
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	123,820	109,629
Demand side management program amortization	1,255	1,255
Deferred income taxes	99,882	35,541
Amortization of investment tax credits	(160)	(255)
Allowance for equity funds used during construction	(7,348)	(5,578)
Net derivative losses	203	201
Other	122	0
Changes in operating assets and liabilities:
Accounts receivable	(22,160)	(24,416)
Accrued unbilled revenues	(18,307)	18,286
Inventories	(1,491)	3,351
Prepayments and other	24,172	(14,589)
Accounts payable	19,690	(6,891)
Net regulatory assets and liabilities	(18,480)	43,980
Other current liabilities	18,989	43,949
Pension and other employee benefit obligations	(15,606)	(9,961)
Change in other noncurrent assets	(537)	1,054
Change in other noncurrent liabilities	3,916	1,227
Net cash provided by operating activities	331,040	301,421
Investing activities
Utility capital/construction expenditures	(371,994)	(428,991)
Proceeds from insurance recoveries	987	0
Allowance for equity funds used during construction	7,348	5,578
Investments in utility money pool arrangement	(75,000)	(9,000)
Repayments from utility money pool arrangement	75,000	9,000
Other	(1,174)	0
Net cash used in investing activities	(364,833)	(423,413)
Financing activities
Repayment of short-term borrowings, net	(15,000)	(37,000)
Proceeds from long-term debt	296,152	198,784
Borrowings under utility money pool arrangement	505,000	407,700
Repayments under utility money pool arrangement	(505,000)	(405,700)
Capital contributions from parent	16,225	34,535
Dividends paid to parent	(57,570)	(76,192)
Net cash provided by financing activities	239,807	122,127
Net change in cash and cash equivalents	206,014	135
Cash and cash equivalents at beginning of period	834	596
Cash and cash equivalents at end of period	206,848	731
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(47,787)	(58,539)
Cash received (paid) for income taxes, net	49,402	(41,114)
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 25,445	$ 29,815