CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating activities
Net income	$ 51,006	$ 42,749	$ 47,363
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	69,900	64,996	62,809
Deferred income taxes	35,610	20,714	8,725
Amortization of investment tax credits	(611)	(622)	(634)
Allowance for equity funds used during construction	(1,007)	(2,253)	(1,637)
Provision for bad debts	3,842	3,294	4,505
Net derivative losses	127	127	1,144
Changes in operating assets and liabilities:
Accounts receivable	(4,013)	15,556	(17,905)
Accrued unbilled revenues	2,911	(6,672)	(2,268)
Inventories	913	1,827	11,033
Other current assets	(1,180)	6,872	(9,019)
Accounts payable	(16,614)	(5,668)	13,344
Net regulatory assets and liabilities	10,008	(3,207)	24,706
Other current liabilities	(2,260)	1,131	(10,794)
Pension and other employee benefit obligations	(7,214)	(3,113)	(1,355)
Change in other noncurrent assets	564	867	822
Change in other noncurrent liabilities	(2,682)	5,260	1,006
Net cash provided by operating activities	139,300	141,858	131,845
Investing activities
Utility capital/construction expenditures	(140,982)	(128,933)	(105,408)
Allowance for equity funds used during construction	1,007	2,253	1,637
Other, net	(112)	2,291	5,140
Net cash used in investing activities	(140,087)	(124,389)	(98,631)
Financing activities
Proceeds from short-term borrowings, net	66,000	0	0
Proceeds from notes payable to affiliate	111,300	302,300	62,500
Repayments of notes payable to affiliates	(148,350)	(280,850)	(47,050)
Repayment of long-term debt	(96)	(95)	(66,890)
Capital contributions from parent	0	40,566	21,797
Dividends paid to parent	(32,941)	(73,868)	(34,259)
Net cash used in financing activities	(4,087)	(11,947)	(63,902)
Net change in cash and cash equivalents	(4,874)	5,522	(30,688)
Cash and cash equivalents at beginning of period	6,445	923	31,611
Cash and cash equivalents at end of period	1,571	6,445	923
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(22,616)	(22,154)	(23,138)
Cash received (paid) for income taxes, net	1,116	4,371	(30,011)
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 9,427	$ 3,630	$ 1,800