BALANCE SHEETS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets
Cash and cash equivalents	$ 1,084	$ 482
Accounts receivable, net	81,259	62,067
Accounts receivable from affiliates	7,822	4,791
Accrued unbilled revenues	124,752	98,892
Inventories	36,895	31,337
Regulatory assets	26,451	24,020
Derivative instruments	7,892	7,892
Deferred income taxes	75,280	27,528
Prepayments and other	29,209	11,387
Total current assets	390,644	268,396
Property, plant and equipment, net	3,174,187	2,861,756
Other assets
Regulatory assets	312,635	324,081
Derivative instruments	43,029	48,949
Other	17,131	14,759
Total other assets	372,795	387,789
Total assets	3,937,626	3,517,941
Current liabilities
Short-term debt	0	9,000
Borrowings under utility money pool arrangement	80,000	0
Accounts payable	147,791	141,327
Accounts payable to affiliates	13,572	12,363
Regulatory liabilities	63,672	75,891
Taxes accrued	29,115	19,380
Accrued interest	26,258	15,104
Dividends payable	18,218	16,773
Derivative instruments	3,592	3,601
Other	70,931	31,084
Total current liabilities	453,149	324,523
Deferred credits and other liabilities
Deferred income taxes	749,288	662,201
Regulatory liabilities	75,089	91,815
Asset retirement obligations	18,239	17,607
Derivative instruments	35,099	37,790
Pension and employee benefit obligations	78,321	97,273
Other	3,618	6,093
Total deferred credits and other liabilities	959,654	912,779
Commitments and contingencies
Capitalization
Long-term debt	1,199,783	1,103,684
Common stock — 200 shares authorized of $1.00 par value; 100 shares outstanding at Sept. 30, 2013 and Dec. 31, 2012, respectively	0	0
Additional paid in capital	968,121	843,186
Retained earnings	358,122	335,101
Accumulated other comprehensive loss	(1,203)	(1,332)
Total common stockholder’s equity	1,325,040	1,176,955
Total liabilities and equity	$ 3,937,626	$ 3,517,941