CONDENSED BALANCE SHEETS (Unaudited) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
CURRENT ASSETS
Accounts receivable, less reserve of $1.7 and $2.6, respectively	$ 146.0	$ 161.5
Accrued unbilled revenues	49.6	57.4
Advances to parent	0	90.3
Fuel inevntories	90.9	76.8
Materials and supplies, at average cost	75.9	74.7
Gas imbalances	0.6	0
Deferred income taxes	19.3	138.7
Fuel clause under recoveries	0.4	0
Other	38.5	34.6
Total current assets	421.2	634.0
OTHER PROPERTY AND INVESTMENTS, at cost	2.7	2.7
PROPERTY, PLANT AND EQUIPMENT
In service	8,581.0	8,498.3
Construction work in progress	350.7	251.4
Total property, plant and equipment	8,931.7	8,749.7
Less accumulated depreciation	2,750.0	2,705.6
Net property, plant and equipment	6,181.7	6,044.1
DEFERRED CHARGES AND OTHER ASSETS
Regulatory assets	502.6	510.6
Other	30.2	31.0
Total deferred charges and other assets	532.8	541.6
TOTAL ASSETS	7,138.4	7,222.4
CURRENT LIABILITIES
Short-term debt	43.1	0
Accounts payable - affiliates	2.1	0.7
Accounts payable - other	203.3	186.7
Advances from parent	54.4	0
Customer deposits	69.5	68.5
Accrued taxes	22.2	35.0
Accrued interest	30.0	43.2
Accrued compensation	21.3	33.2
Price risk management	1.3	2.1
Fuel clause over recoveries	81.6	109.2
Other	54.9	53.9
Total current liabilities	583.7	532.5
LONG-TERM DEBT	2,050.3	2,050.3
DEFERRED CREDITS AND OTHER LIABILITIES
Accrued benefit obligations	238.4	240.9
Deferred income taxes	1,270.7	1,377.8
Deferred investment tax credits	3.4	3.9
Regulatory liabilities	245.5	245.1
Deferred revenue	0.1	0
Other	69.1	68.8
Total deferred credits and other liabilities	1,827.2	1,936.5
Total liabilities	4,461.2	4,519.3
COMMITMENTS AND CONTINGENCIES (NOTE 9)
STOCKHOLDER'S EQUITY
Common stockholder's equity	1,014.6	1,014.0
Retained earnings	1,663.4	1,690.4
Accumulated other comprehensive loss, net of tax	(0.8)	(1.3)
Total stockholder's equity	2,677.2	2,703.1
TOTAL LIABILITIES AND STOCKHOLDER'S EQUITY	$ 7,138.4	$ 7,222.4