CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating activities
Net income	$ 24,235	$ 19,685
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	19,590	19,139
Deferred income taxes	10,069	7,136
Amortization of investment tax credits	(168)	(166)
Allowance for equity funds used during construction	(1,572)	(946)
Net derivative losses	437	31
Changes in operating assets and liabilities:
Accounts receivable	(13,722)	(10,454)
Accrued unbilled revenues	12,194	8,559
Inventories	6,980	4,633
Other current assets	11,145	7,671
Accounts payable	12,378	(6,337)
Net regulatory assets and liabilities	(20,462)	2,541
Other current liabilities	2,936	3,086
Pension and other employee benefit obligations	(8,007)	(10,860)
Change in other noncurrent assets	23	202
Change in other noncurrent liabilities	160	50
Net cash provided by operating activities	56,216	43,970
Investing activities
Utility capital/construction expenditures	(59,699)	(39,370)
Allowance for equity funds used during construction	1,572	946
Other, net	(41)	(96)
Net cash used in investing activities	(58,168)	(38,520)
Financing activities
Proceeds from (repayments of) short-term borrowings, net	11,000	(18,000)
Repayments of long-term debt	(18)	(72)
Capital contributions from parent	0	20,000
Dividends paid to parent	(8,032)	(7,667)
Net cash provided by (used) in financing activities	2,950	(5,739)
Net change in cash and cash equivalents	998	(289)
Cash and cash equivalents at beginning of period	1,349	4,459
Cash and cash equivalents at end of period	2,347	4,170
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(5,827)	(6,104)
Cash received for income taxes, net	5,573	697
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	$ 16,436	$ 6,627