CONSOLIDATED BALANCE SHEETS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets
Cash and cash equivalents	$ 3,857	$ 5,150
Accounts receivable, net	272,988	277,461
Accounts receivable from affiliates	13,503	93,544
Investments in utility money pool arrangement	86,000	0
Accrued unbilled revenues	228,822	285,624
Inventories	191,671	223,794
Regulatory assets	158,975	143,689
Deferred income taxes	35,904	0
Derivative instruments	6,489	4,889
Prepayments and other	31,718	22,970
Total current assets	1,029,927	1,057,121
Property, plant and equipment, net	10,321,636	10,030,991
Other assets
Regulatory assets	907,695	934,728
Derivative instruments	7,761	10,868
Other	53,596	50,461
Total other assets	969,052	996,057
Total assets	12,320,615	12,084,169
Current liabilities
Current portion of long-term debt	281,676	256,297
Short-term debt	0	154,000
Accounts payable	326,969	359,969
Accounts payable to affiliates	25,778	30,001
Regulatory liabilities	61,066	33,723
Taxes accrued	95,579	153,614
Accrued interest	48,453	48,014
Dividends payable to parent	65,461	66,803
Derivative instruments	8,476	8,753
Other	64,650	72,669
Total current liabilities	978,108	1,183,843
Deferred credits and other liabilities
Deferred income taxes	1,955,825	1,782,828
Deferred investment tax credits	40,654	42,097
Regulatory liabilities	429,969	417,404
Asset retirement obligations	43,933	43,751
Derivative instruments	25,987	30,605
Customer advances	237,642	229,498
Pension and employee benefit obligations	280,581	324,625
Other	66,533	69,307
Total deferred credits and other liabilities	3,081,124	2,940,115
Commitments and contingencies
Capitalization
Long-term debt	3,593,671	3,374,476
Common stock – 100 shares authorized at $0.01 par value; 100 shares outstanding at June 30, 2013 and Dec. 31, 2012	0	0
Additional paid in capital	3,416,129	3,415,669
Retained earnings	1,274,703	1,192,937
Accumulated other comprehensive loss	(23,120)	(22,871)
Total common stockholder’s equity	4,667,712	4,585,735
Total liabilities and equity	$ 12,320,615	$ 12,084,169