BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 482	$ 650
Accounts receivable, net	62,067	65,030
Accounts receivable from affiliates	4,791	1,314
Accrued unbilled revenues	98,892	104,142
Inventories	31,337	35,575
Regulatory assets	24,020	25,244
Derivative instruments	7,892	7,892
Deferred income taxes	27,528	18,247
Prepayments and other	11,387	7,486
Total current assets	268,396	265,580
Property, plant and equipment, net	2,861,756	2,594,732
Other assets
Regulatory assets	324,081	294,813
Derivative instruments	48,949	56,841
Other	14,759	11,883
Total other assets	387,789	363,537
Total assets	3,517,941	3,223,849
Current liabilities
Short-term debt	9,000	0
Borrowings under utility money pool arrangement	0	5,000
Accounts payable	141,327	140,412
Accounts payable to affiliates	12,363	11,828
Regulatory liabilities	75,891	57,104
Taxes accrued	19,380	19,910
Accrued interest	15,104	13,842
Dividends payable	16,773	16,913
Derivative instruments	3,601	3,601
Other	31,084	29,841
Total current liabilities	324,523	298,451
Deferred credits and other liabilities
Deferred income taxes	662,201	596,581
Regulatory liabilities	91,815	105,335
Asset retirement obligations	17,607	27,266
Derivative instruments	37,790	41,391
Pension and employee benefit obligations	97,273	76,307
Other	6,093	8,345
Total deferred credits and other liabilities	912,779	855,225
Commitments and contingencies
Capitalization
Long-term debt	1,103,684	993,314
Common stock - 200 shares authorized of $1.00 par value; 100 shares outstanding at Dec. 31, 2012 and Dec. 31, 2011	0	0
Additional paid in capital	843,186	783,162
Retained earnings	335,101	295,201
Accumulated other comprehensive loss	(1,332)	(1,504)
Total common stockholder's equity	1,176,955	1,076,859
Total liabilities and equity	$ 3,517,941	$ 3,223,849