CONDENSED BALANCE SHEETS (Unaudited) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
CURRENT ASSETS
Accounts receivable, less reserve of $2.8 and $3.7, respectively	$ 267.6	$ 182.4
Accrued unbilled revenues	62.5	59.3
Advances to parent	40.7	97.2
Fuel inevntories	69.5	76.9
Materials and supplies, at average cost	84.6	81.1
Deferred income taxes	124.8	10.3
Fuel clause under recoveries	0.8	1.8
Other	39.3	28.0
Total current assets	689.8	537.0
OTHER PROPERTY AND INVESTMENTS, at cost	2.6	2.7
PROPERTY, PLANT AND EQUIPMENT
In service	8,347.0	7,808.8
Construction work in progress	207.8	334.4
Total property, plant and equipment	8,554.8	8,143.2
Less accumulated depreciation	2,675.6	2,592.3
Net property, plant and equipment	5,879.2	5,550.9
DEFERRED CHARGES AND OTHER ASSETS
Regulatory assets	480.9	507.9
Other	29.8	22.4
Total deferred charges and other assets	510.7	530.3
TOTAL ASSETS	7,082.3	6,620.9
CURRENT LIABILITIES
Accounts payable - affiliates	0	1.3
Accounts payable - other	119.9	193.4
Customer deposits	67.7	65.7
Accrued taxes	50.9	33.5
Accrued interest	30.0	43.2
Accrued compensation	30.7	26.6
Price risk management	2.0	2.2
Gas imbalances	0.1	0
Fuel clause over recoveries	107.1	7.7
Other	75.6	56.5
Total current liabilities	484.0	430.1
LONG-TERM DEBT	2,050.2	2,039.2
DEFERRED CREDITS AND OTHER LIABILITIES
Accrued benefit obligations	200.7	230.8
Deferred income taxes	1,355.7	1,146.0
Deferred investment tax credits	4.5	6.1
Regulatory liabilities	243.6	230.7
Price risk management	0.5	1.8
Other	68.6	42.2
Total deferred credits and other liabilities	1,873.6	1,657.6
Total liabilities	4,407.8	4,126.9
COMMITMENTS AND CONTINGENCIES (NOTE 9)
STOCKHOLDER'S EQUITY
Common stockholder's equity	1,013.2	1,011.4
Retained earnings	1,662.8	1,485.1
Accumulated other comprehensive loss, net of tax	(1.5)	(2.5)
Total stockholder's equity	2,674.5	2,494.0
TOTAL LIABILITIES AND STOCKHOLDER'S EQUITY	$ 7,082.3	$ 6,620.9