CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Plant and property, at original cost:
Electric and water	$ 2,094,840	$ 2,074,748
Natural gas	67,263	66,918
Other	35,584	34,984
Construction work in progress	36,891	24,141
Total plant and property, Gross	2,234,578	2,200,791
Accumulated depreciation and amortization	649,363	637,139
Total plant and property, Net	1,585,215	1,563,652
Current assets:
Cash and cash equivalents	2,269	5,408
Restricted cash	4,357	4,357
Accounts receivable - trade, net of allowance of $1,505 and $1,138, respectively	41,677	42,296
Accrued unbilled revenues	10,978	20,326
Accounts receivable - other	19,441	16,269
Fuel, materials and supplies	62,193	62,239
Prepaid expenses and other	11,874	14,629
Regulatory assets	3,885	7,724
Total current assets	156,674	173,248
Noncurrent assets and deferred charges:
Regulatory assets	231,428	231,922
Goodwill	39,492	39,492
Unamortized debt issuance costs	9,040	9,331
Other	4,610	4,190
Total noncurrent assets and deferred charges	284,570	284,935
Total Assets	2,026,459	2,021,835
Capitalization and Liabilities
Common stock, $1 par value, 42,114,630 and 41,977,725 shares issued and outstanding, respectively	42,115	41,978
Capital in excess of par value	621,306	618,304
Retained earnings	32,997	33,707
Total common stockholders' equity	696,418	693,989
Long-term debt (net of current portion):
Obligations under capital lease	4,666	4,739
First mortgage bonds and secured debt	399,764	487,948
Unsecured debt	199,590	199,572
Total long-term debt	604,020	692,259
Total long-term debt and common stockholders' equity	1,300,438	1,386,248
Current liabilities:
Accounts payable and accrued liabilities	43,605	59,307
Current maturities of long-term debt	75,773	933
Short-term debt	22,500	12,000
Customer deposits	11,671	11,428
Interest accrued	12,022	5,958
Unrealized loss in fair value of derivative contracts	6,171	4,769
Taxes accrued	7,177	2,634
Total current liabilities	178,919	97,029
Commitments and contingencies (Note 7)
Noncurrent liabilities and deferred credits:
Regulatory liabilities	131,667	128,440
Deferred income taxes	268,577	263,933
Unamortized investment tax credits	19,165	19,226
Pension and other postretirement benefit obligations	102,071	103,371
Unrealized loss in fair value of derivative contracts	6,028	5,081
Other	19,594	18,507
Total noncurrent liabilities and deferred credits	547,102	538,558
Total Capitalization and Liabilities	$ 2,026,459	$ 2,021,835