CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating activities
Net income	$ 362,354	$ 380,170
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	287,141	271,150
Demand side management program amortization	3,309	3,658
Deferred income taxes	120,585	230,665
Amortization of investment tax credits	(2,202)	(2,219)
Allowance for equity funds used during construction	(36,697)	(21,529)
Net realized and unrealized hedging and derivative transactions	(6,946)	(9,052)
Changes in operating assets and liabilities:
Accounts receivable	55,070	61,660
Accrued unbilled revenues	58,758	80,347
Inventories	(26,409)	(28,021)
Prepayments and other	1,001	5,818
Accounts payable	(86,984)	(28,581)
Net regulatory assets and liabilities	110,692	74,709
Other current liabilities	(43,323)	(16,662)
Pension and other employee benefit obligations	(37,769)	(44,101)
Change in other noncurrent assets	5,353	6,917
Change in other noncurrent liabilities	(15,355)	7,744
Net cash provided by operating activities	748,578	972,673
Investing activities
Utility capital/construction expenditures	(832,270)	(742,822)
Allowance for equity funds used during construction	36,697	21,529
Investments in utility money pool arrangement	(587,000)	(1,086,000)
Repayments from utility money pool arrangement	659,000	951,000
Net cash used in investing activities	(723,573)	(856,293)
Financing activities
Proceeds from (repayments of) short-term borrowings, net	253,000	(154,000)
Borrowings under utility money pool arrangement	303,000	14,000
Repayments under utility money pool arrangement	(292,000)	(14,000)
Proceeds from issuance of long-term debt	295,601	492,372
Repayments of long-term debt	(275,000)	(250,000)
Contributions from Parent	35,486	4,485
Dividends paid to parent	(355,547)	(198,941)
Net cash used in financing activities	(35,460)	(106,084)
Net change in cash and cash equivalents	(10,455)	10,296
Cash and cash equivalents at beginning of period	21,089	5,150
Cash and cash equivalents at end of period	10,634	15,446
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(136,045)	(131,378)
Cash (paid) received for income taxes, net	(67,717)	41,531
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 125,498	$ 100,475