CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Assets
Cash and cash equivalents	$ 26.1	$ 27.4
Collateral on deposit	61.1	41.0
Accounts receivable and accrued unbilled revenues, net of reserves of $45.3 and $43.5, respectively	625.3	796.8
Inventories	341.7	271.9
Current assets from risk management activities	154.9	145.4
Current regulatory assets	101.7	110.8
Assets held for sale	0.7	10.1
Deferred income taxes	38.4	64.3
Prepaid taxes	141.8	152.8
Other current assets	30.0	38.6
Current assets	1,521.7	1,659.1
Property, plant, and equipment, net of accumulated depreciation of $3,307.9 and $3,114.7, respectively	6,198.8	5,501.9
Long-term regulatory assets	1,784.6	1,813.8
Long-term assets from risk management activities	58.1	45.3
Equity method investments	534.5	512.2
Goodwill	662.1	658.3
Other long-term assets	161.5	136.8
Total assets	10,921.3	10,327.4
Liabilities and Equity
Short-term debt	388.0	482.4
Current portion of long-term debt	276.5	313.5
Accounts payable	475.4	457.7
Current liabilities from risk management activities	157.5	181.9
Accrued taxes	41.2	83.0
Current regulatory liabilities	56.1	65.6
Liabilities held for sale	0	0.2
Other current liabilities	237.9	229.0
Current liabilities	1,632.6	1,813.3
Long-term debt	2,506.2	1,931.7
Deferred income taxes	1,320.4	1,203.8
Deferred investment tax credits	48.4	49.3
Long-term regulatory liabilities	390.4	370.5
Environmental remediation liabilities	613.6	651.5
Pension and other postretirement benefit obligations	573.0	625.2
Long-term liabilities from risk management activities	59.6	58.4
Asset retirement obligations	426.8	411.2
Other long-term liabilities	138.8	135.7
Long-term liabilities	6,077.2	5,437.3
Commitments and contingencies
Common stock – $1 par value; 200,000,000 shares authorized; 79,757,715 shares issued; 79,289,748 shares outstanding	79.8	78.3
Additional paid-in capital	2,648.1	2,574.6
Retained earnings	489.8	431.5
Accumulated other comprehensive loss	(35.7)	(40.9)
Shares in deferred compensation trust	(22.7)	(17.7)
Total common shareholders’ equity	3,159.3	3,025.8
Preferred stock of subsidiary – $100 par value; 1,000,000 shares authorized; 511,882 shares issued; 510,495 shares outstanding	51.1	51.1
Noncontrolling interest in subsidiaries	1.1	(0.1)
Total liabilities and equity	$ 10,921.3	$ 10,327.4