CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Operating activities
Net income	$ 208,195	$ 213,904
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	190,911	181,222
Demand side management program amortization	2,288	2,514
Deferred income taxes	65,725	127,490
Amortization of investment tax credits	(1,468)	(1,479)
Allowance for equity funds used during construction	(24,382)	(12,714)
Net realized and unrealized hedging and derivative transactions	(2,892)	(5,094)
Changes in operating assets and liabilities:
Accounts receivable	20,170	83,949
Accrued unbilled revenues	53,838	56,802
Inventories	31,490	32,123
Prepayments and other	4,636	(8,183)
Accounts payable	(83,451)	(16,087)
Net regulatory assets and liabilities	51,798	64,131
Other current liabilities	(69,978)	(63,653)
Pension and other employee benefit obligations	(36,769)	(44,007)
Change in other noncurrent assets	5,811	479
Change in other noncurrent liabilities	(7,313)	2,860
Net cash provided by operating activities	408,609	614,257
Investing activities
Utility capital/construction expenditures	(573,401)	(497,626)
Allowance for equity funds used during construction	24,382	12,714
Investments in utility money pool arrangement	(567,000)	(617,000)
Repayments from utility money pool arrangement	639,000	531,000
Net cash used in investing activities	(477,019)	(570,912)
Financing activities
Proceeds from (repayments of) short-term borrowings, net	256,800	(154,000)
Borrowings under utility money pool arrangement	129,000	14,000
Repayments under utility money pool arrangement	(129,000)	(14,000)
Proceeds from issuance of long-term debt	295,642	492,383
Repayments of long-term debt	(275,000)	(250,000)
Contributions from Parent	35,486	460
Dividends paid to parent	(259,156)	(133,481)
Net cash provided by (used in) financing activities	53,772	(44,638)
Net change in cash and cash equivalents	(14,638)	(1,293)
Cash and cash equivalents at beginning of period	21,089	5,150
Cash and cash equivalents at end of period	6,451	3,857
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(74,848)	(76,228)
Cash paid for income taxes, net	(39,649)	(14,922)
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 104,927	$ 73,152