CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating activities
Net income	$ 19,685	$ 14,878
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	19,139	17,319
Deferred income taxes	7,136	5,304
Amortization of investment tax credits	(166)	(157)
Allowance for equity funds used during construction	(946)	(999)
Net derivative losses	31	32
Changes in operating assets and liabilities:
Accounts receivable	(10,454)	(7,818)
Accrued unbilled revenues	8,559	14,184
Inventories	4,633	7,886
Other current assets	7,671	6,395
Accounts payable	(6,337)	(3,996)
Net regulatory assets and liabilities	2,541	3,359
Other current liabilities	3,086	2,082
Pension and other employee benefit obligations	(10,860)	(12,473)
Change in other noncurrent assets	202	(197)
Change in other noncurrent liabilities	50	(21)
Net cash provided by operating activities	43,970	45,778
Investing activities
Utility capital/construction expenditures	(39,370)	(36,748)
Allowance for equity funds used during construction	946	999
Other, net	(96)	1,034
Net cash used in investing activities	(38,520)	(34,715)
Financing activities
(Repayments of) proceeds from short-term borrowings, net	(18,000)	5,000
Proceeds from notes payable to affiliate	0	50
Repayments of long-term debt	(72)	(16)
Capital contributions from parent	20,000	0
Dividends paid to parent	(7,667)	(16,225)
Net cash used in financing activities	(5,739)	(11,191)
Net change in cash and cash equivalents	(289)	(128)
Cash and cash equivalents at beginning of period	4,459	1,571
Cash and cash equivalents at end of period	4,170	1,443
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(6,104)	(6,546)
Cash received (paid) for income taxes, net	697	(833)
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 6,627	$ 4,406