CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities
Net income	$ 115,874	$ 110,966
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	109,715	101,172
Demand side management program amortization	733	1,022
Deferred income taxes	64,562	37,771
Amortization of Investment Tax Credits	(701)	(733)
Allowance for equity funds used during construction	(4,318)	(2,806)
Net realized and unrealized hedging and derivative transactions	2,782	5,086
Other Operating Activities, Cash Flow Statement	(388)	0
Changes in operating assets and liabilities:
Accounts receivable	39,022	35,312
Accrued unbilled revenues	80,374	89,193
Inventories	40,165	43,638
Prepayments and other	76,646	89,210
Accounts payable	(32,194)	(61,624)
Net regulatory assets and liabilities	(27,163)	73,340
Other current liabilities	15,458	43,420
Pension and other employee benefit obligations	(16,318)	(20,496)
Change in other noncurrent assets	595	903
Change in other noncurrent liabilities	(7,944)	(3,734)
Net cash provided by operating activities	456,900	541,640
Investing activities
Utility capital/construction expenditures	(238,635)	(241,194)
Allowance for equity funds used during construction	4,318	2,806
Investments in utility money pool arrangement	(314,000)	(57,000)
Repayments from utility money pool arrangement	221,000	73,000
Payments for (Proceeds from) Other Investing Activities	683	0
Net cash used in investing activities	(326,634)	(222,388)
Financing activities
Repayments of short-term borrowings, net	(14,000)	(240,000)
Borrowings under utility money pool arrangement	0	9,000
Repayments under utility money pool arrangement	0	(9,000)
Proceeds from Contributions from Parent	(31,162)	0
Dividends paid to parent	(83,374)	(83,794)
Net cash used in financing activities	(128,536)	(323,794)
Net change in cash and cash equivalents	1,730	(4,542)
Cash and cash equivalents at beginning of period	3,585	7,635
Cash and cash equivalents at end of period	5,315	3,093
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(65,225)	(64,940)
Cash received for income taxes, net	74,941	87,443
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 68,817	$ 65,289