CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Operating activities
Net income	$ 52,242	$ 42,820
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	58,126	52,291
Deferred income taxes	19,491	19,604
Amortization of investment tax credits	(500)	(469)
Allowance for equity funds used during construction	(2,755)	(1,379)
Net derivative (gains) losses	(658)	95
Changes in operating assets and liabilities:
Accounts receivable	2,566	(11,303)
Accrued unbilled revenues	11,076	9,496
Inventories	(3,382)	3,924
Other current assets	9,486	6,142
Accounts payable	(3,755)	(7,307)
Net regulatory assets and liabilities	(6,260)	6,150
Other current liabilities	9,635	9,701
Pension and other employee benefit obligations	(9,273)	(11,002)
Change in other noncurrent assets	260	(119)
Change in other noncurrent liabilities	1,555	(500)
Net cash provided by operating activities	137,854	118,144
Investing activities
Utility capital/construction expenditures	(134,641)	(106,553)
Allowance for equity funds used during construction	2,754	1,379
Other, net	(249)	1,096
Net cash used in investing activities	(132,136)	(104,078)
Financing activities
(Repayments of) proceeds from short-term borrowings, net	(28,000)	33,000
(Repayments of) proceeds from notes payable to affiliate	(80)	50
Repayments of long-term debt	(109)	(48)
Capital contributions from parent	42,481	2,162
Dividends paid to parent	(22,943)	(49,306)
Net cash used in financing activities	(8,651)	(14,142)
Net change in cash and cash equivalents	(2,933)	(76)
Cash and cash equivalents at beginning of period	4,459	1,571
Cash and cash equivalents at end of period	1,526	1,495
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(18,366)	(16,925)
Cash received (paid) for income taxes, net	(2,127)	1,971
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 10,347	$ 8,866