CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Operating activities
Net income	$ 213,904	$ 188,692
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	181,222	166,460
Demand side management program amortization	2,514	2,785
Deferred income taxes	127,490	117,034
Amortization of investment tax credits	(1,479)	(1,303)
Allowance for equity funds used during construction	(12,714)	(6,274)
Net realized and unrealized hedging and derivative transactions	(5,094)	5,953
Changes in operating assets and liabilities:
Accounts receivable	83,949	57,355
Accrued unbilled revenues	56,802	100,953
Inventories	32,123	69,268
Prepayments and other	(8,183)	(34,380)
Accounts payable	(16,087)	(106,008)
Net regulatory assets and liabilities	64,131	(33,991)
Other current liabilities	(63,653)	(54,416)
Pension and other employee benefit obligations	(44,007)	(38,190)
Change in other noncurrent assets	479	(7,450)
Change in other noncurrent liabilities	2,860	(4,737)
Net cash provided by operating activities	614,257	421,751
Investing activities
Utility capital/construction expenditures	(497,626)	(382,676)
Allowance for equity funds used during construction	12,714	6,274
Investments in utility money pool arrangement	(617,000)	(610,000)
Repayments from utility money pool arrangement	531,000	662,000
Net cash used in investing activities	(570,912)	(324,402)
Financing activities
(Repayments of) proceeds from short-term borrowings, net	(154,000)	5,000
Borrowings under utility money pool arrangement	14,000	19,000
Repayments under utility money pool arrangement	(14,000)	(14,000)
Proceeds from issuance of long-term debt	492,383	0
Repayments of long-term debt	(250,000)	0
Capital contributions from parent	460	28,122
Dividends paid to parent	133,481	134,004
Net cash used in financing activities	(44,638)	(95,882)
Net change in cash and cash equivalents	(1,293)	1,467
Cash and cash equivalents at beginning of period	5,150	3,763
Cash and cash equivalents at end of period	3,857	5,230
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(76,228)	(90,642)
Cash paid for income taxes, net	(14,922)	(33,342)
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 73,152	$ 58,967