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	$ 30,229	$ 20,620
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	38,476	34,680
Deferred income taxes	15,407	14,638
Amortization of investment tax credits	(332)	(312)
Allowance for equity funds used during construction	(1,726)	(1,764)
Net derivative (gains) losses	(344)	63
Changes in operating assets and liabilities:
Accounts receivable	1,134	(9,458)
Accrued unbilled revenues	9,928	9,625
Inventories	1,913	7,696
Other current assets	3,442	(712)
Accounts payable	(5,435)	1,860
Net regulatory assets and liabilities	(806)	4,479
Other current liabilities	1,670	588
Pension and other employee benefit obligations	(10,234)	(11,730)
Change in other noncurrent assets	329	(228)
Change in other noncurrent liabilities	630	582
Net cash provided by operating activities	84,281	70,627
Investing activities
Utility capital/construction expenditures	(81,603)	(72,230)
Allowance for equity funds used during construction	1,726	1,764
Other, net	(230)	1,105
Net cash used in investing activities	(80,107)	(69,361)
Financing activities
(Repayments of) proceeds from short-term borrowings, net	(37,000)	13,000
(Repayments of) proceeds from notes payable to affiliate	(80)	50
Repayments of long-term debt	(92)	(32)
Capital contributions from parent	45,093	2,162
Dividends paid to parent	(15,186)	(16,225)
Net cash used in financing activities	(7,265)	(1,045)
Net change in cash and cash equivalents	(3,091)	221
Cash and cash equivalents at beginning of period	4,459	1,571
Cash and cash equivalents at end of period	1,368	1,792
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(12,122)	(11,302)
Cash received (paid) for income taxes, net	39	(706)
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 9,134	$ 5,748