CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities
Net income	$ 376,825	$ 382,547
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	332,383	309,048
Demand side management program amortization	1,802	2,776
Deferred income taxes	202,599	185,212
Amortization of investment tax credits	(2,104)	(2,200)
Allowance for equity funds used during construction	(13,714)	(10,155)
Net realized and unrealized hedging and derivative transactions	(1,801)	3,255
Other	(388)	0
Changes in operating assets and liabilities:
Accounts receivable	27,080	61,044
Accrued unbilled revenues	70,498	92,819
Inventories	(11,712)	1,215
Prepayments and other	52,526	75,488
Accounts payable	(20,164)	(78,610)
Net regulatory assets and liabilities	(31,152)	43,125
Other current liabilities	(59,596)	(36,587)
Pension and other employee benefit obligations	(13,080)	(22,653)
Change in other noncurrent assets	(1,422)	2,273
Change in other noncurrent liabilities	(15,433)	(30,667)
Net cash provided by operating activities	893,147	977,930
Investing activities
Utility capital/construction expenditures	(802,051)	(668,381)
Proceeds from insurance recoveries	608	0
Allowance for equity funds used during construction	13,714	10,155
Investments in utility money pool arrangement	(437,000)	(150,300)
Repayments from utility money pool arrangement	437,000	166,300
Other	(1,460)	0
Net cash used in investing activities	(789,189)	(642,226)
Financing activities
Repayments of short-term borrowings, net	(14,000)	(382,000)
Borrowings under utility money pool arrangement	357,000	67,000
Repayments under utility money pool arrangement	(306,000)	(67,000)
Proceeds from issuance of long-term debt	244,527	246,826
Repayments of long-term debt	(129,500)	0
Contributions from parent	1,571	73,718
Dividends paid to parent	(253,796)	(247,174)
Net cash used in financing activities	(100,198)	(308,630)
Net change in cash and cash equivalents	3,760	27,074
Cash and cash equivalents at beginning of period	3,585	7,635
Cash and cash equivalents at end of period	7,345	34,709
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(149,786)	(145,569)
Cash received for income taxes, net	32,388	38,349
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 84,417	$ 104,965