CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Plant and property, at original cost:
Electric	$ 2,277,745	$ 2,219,605
Gas	79,054	72,834
Other	41,295	39,902
Construction work in progress	216,801	152,330
Total plant and property, Gross	2,614,895	2,484,671
Accumulated depreciation and amortization	753,309	732,737
Total plant and property, Net	1,861,586	1,751,934
Current assets:
Cash and cash equivalents	2,254	3,475
Restricted cash	7,726	2,872
Accounts receivable - trade, net of allowance $957 and $1,025, respectively	53,703	50,137
Accrued unbilled revenues	16,567	26,694
Accounts receivable - other	14,903	13,101
Fuel, materials and supplies	54,501	48,811
Prepaid expenses and other	21,257	15,954
Unrealized gain in fair value of derivative contracts	4,579	2,469
Regulatory assets	11,019	7,743
Total current assets	186,509	171,256
Noncurrent assets and deferred charges:
Regulatory assets	156,549	169,333
Goodwill	39,492	39,492
Unamortized debt issuance costs	8,348	8,826
Unrealized gain in fair value of derivative contracts		41
Other	2,842	4,163
Total noncurrent assets and deferred charges	207,231	221,855
Total Assets	2,255,326	2,145,045
Capitalization and Liabilities
Common stock, $1 par value, 43,416,933 and 43,044,185 shares issued and outstanding, respectively	43,417	43,044
Capital in excess of par value	647,566	639,525
Retained earnings	90,460	67,554
Total common stockholders' equity	781,443	750,123
Long-term debt (net of current portion):
Obligations under capital lease	3,950	4,167
First mortgage bonds and secured debt	637,606	637,578
Unsecured debt	101,695	101,683
Total long-term debt	743,251	743,428
Total long-term debt and common stockholders' equity	1,524,694	1,493,551
Current liabilities:
Accounts payable and accrued liabilities	59,350	71,375
Current maturities of long-term debt	299	274
Short-term debt	63,000	4,000
Regulatory liabilities	7,916	5,681
Customer deposits	13,155	12,543
Interest accrued	14,038	6,352
Other current liabilities	5,904	299
Unrealized loss in fair value of derivative contracts	2,380	1,889
Taxes accrued	19,659	3,386
Total current liabilities	185,701	105,799
Commitments and contingencies (Note 7)
Noncurrent liabilities and deferred credits:
Regulatory liabilities	129,221	132,012
Deferred income taxes	335,908	324,266
Unamortized investment tax credits	18,380	18,431
Pension and other postretirement benefit obligations	43,726	51,405
Unrealized loss in fair value of derivative contracts	1,471	2,799
Other	16,225	16,782
Total noncurrent liabilities and deferred credits	544,931	545,695
Total Capitalization and Liabilities	$ 2,255,326	$ 2,145,045