CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Plant and property, at original cost:
Electric and water	$ 2,251,750	$ 2,219,605
Natural gas	73,291	72,834
Other	40,601	39,902
Construction work in progress	159,689	152,330
Total plant and property, Gross	2,525,331	2,484,671
Accumulated depreciation and amortization	737,442	732,737
Total plant and property, Net	1,787,889	1,751,934
Current assets:
Cash and cash equivalents	4,145	3,475
Restricted cash	2,276	2,872
Accounts receivable - trade, net of allowance of $1,578 and $1,025, respectively	58,160	50,137
Accrued unbilled revenues	18,154	26,694
Accounts receivable - other	6,975	13,101
Fuel, materials and supplies	44,521	48,811
Prepaid expenses and other	16,403	15,954
Unrealized gain in fair value of derivative contracts	2,706	2,469
Regulatory assets	11,047	7,743
Total current assets	164,387	171,256
Noncurrent assets and deferred charges:
Regulatory assets	164,219	169,333
Goodwill	39,492	39,492
Unamortized debt issuance costs	8,674	8,826
Unrealized gain in fair value of derivative contracts	21	41
Other	3,789	4,163
Total noncurrent assets and deferred charges	216,195	221,855
Total Assets	2,168,471	2,145,045
Capitalization and Liabilities
Common stock, $1 par value, 43,181,137 and 43,044,185 shares issued and outstanding, respectively	43,181	43,044
Capital in excess of par value	642,783	639,525
Retained earnings	77,465	67,554
Total common stockholders' equity	763,429	750,123
Long-term debt (net of current portion):
Obligations under capital lease	4,096	4,167
First mortgage bonds and secured debt	637,587	637,578
Unsecured debt	101,687	101,683
Total long-term debt	743,370	743,428
Total long-term debt and common stockholders' equity	1,506,799	1,493,551
Current liabilities:
Accounts payable and accrued liabilities	52,644	71,375
Current maturities of long-term debt	301	274
Short-term debt	4,500	4,000
Regulatory liabilities	5,619	5,681
Customer deposits	12,708	12,543
Interest accrued	13,809	6,352
Other current liabilities	4,229	299
Unrealized loss in fair value of derivative contracts	1,466	1,889
Taxes accrued	16,545	3,386
Total current liabilities	111,821	105,799
Commitments and contingencies (Note 7)
Noncurrent liabilities and deferred credits:
Regulatory liabilities	135,361	132,012
Deferred income taxes	323,967	324,266
Unamortized investment tax credits	18,460	18,431
Pension and other postretirement benefit obligations	52,548	51,405
Unrealized loss in fair value of derivative contracts	2,570	2,799
Other	16,945	16,782
Total noncurrent liabilities and deferred credits	549,851	545,695
Total Capitalization and Liabilities	$ 2,168,471	$ 2,145,045