Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Plant and property, at original cost:
Electric	$ 2,437,271	$ 2,420,824
Gas	80,893	79,364
Other	41,462	41,394
Construction work in progress	172,335	112,097
Total plant and property, Gross	2,731,961	2,653,679
Accumulated depreciation and amortization	747,204	743,407
Total plant and property, Net	1,984,757	1,910,272
Current assets:
Cash and cash equivalents	1,992	2,105
Restricted cash	4,727	4,726
Accounts receivable - trade, net of allowance of $692 and $1,021 respectively	43,068	45,444
Accrued unbilled revenues	20,546	25,945
Accounts receivable - other	24,559	41,256
Fuel, materials and supplies	58,100	57,799
Prepaid expenses and other	32,017	27,879
Unrealized gain in fair value of derivative contracts	3,260	3,901
Regulatory assets	7,955	10,752
Total current assets	196,224	219,807
Noncurrent assets and deferred charges:
Regulatory assets	202,134	209,717
Goodwill	39,492	39,492
Unamortized debt issuance costs	8,511	8,821
Other	3,627	2,147
Total noncurrent assets and deferred charges	253,764	260,177
Total Assets	2,434,745	2,390,256
Capitalization and liabilities
Common stock, $1 par value, 43,689,223 and 43,479,186 shares issued and outstanding, respectively	43,689	43,479
Capital in excess of par value	653,923	649,543
Retained earnings	89,012	90,276
Total common stockholders' equity	786,624	783,298
Long-term debt (net of current portion):
Obligations under capital lease	3,723	3,875
First mortgage bonds and secured debt	697,634	697,615
Unsecured debt	101,706	101,699
Total long-term debt	803,063	803,189
Total long-term debt and common stockholders' equity	1,589,687	1,586,487
Current liabilities:
Accounts payable and accrued liabilities	52,660	83,420
Current maturities of long-term debt	301	292
Short-term debt	97,000	44,000
Regulatory liabilities	7,477	7,898
Customer deposits	14,003	13,747
Interest accrued	6,821	6,565
Unrealized loss in fair value of derivative contracts	3,967	6,469
Taxes accrued	13,700	3,380
Other current liabilities	440	356
Total current liabilities	$ 196,369	$ 166,127
Commitments and contingencies (Note 7)
Noncurrent liabilities and deferred credits:
Regulatory liabilities	$ 135,319	$ 128,471
Deferred income taxes	391,995	377,452
Unamortized investment tax credits	18,370	18,367
Pension and other postretirement benefit obligations	73,816	93,863
Unrealized loss in fair value of derivative contracts	4,245	3,243
Other	24,944	16,246
Total noncurrent liabilities	648,689	637,642
Total Capitalization and Liabilities	$ 2,434,745	$ 2,390,256