Consolidated Condensed Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Operating Activities
Net Income	$ 295.6	$ 291.4
Reconciliation to cash
Depreciation and amortization	197.7	183.8
Deferred income taxes and investment tax credits, net	143.1	141.2
Contributions to qualified benefit plans	0	0
Change in -
Accounts receivable and accrued revenues	49.3	96.2
Inventories	42.8	47.0
Other current assets	13.8	16.7
Accounts payable	(86.6)	(60.2)
Accrued income taxes, net	16.2	5.7
Other current liabilities	(2.9)	(27.5)
Other, net	12.5	(85.6)
Cash Provided by Operating Activities	681.5	608.7
Investing Activities
Capital expenditures	(307.3)	(314.0)
Investment in transmission affiliate	(5.2)	(6.6)
Change in restricted cash	2.7	27.6
Other, net	(26.8)	(19.6)
Cash Used in Investing Activities	(336.6)	(312.6)
Financing Activities
Exercise of stock options	40.7	38.6
Purchase of common stock	(135.7)	(77.0)
Dividends paid on common stock	(155.6)	(138.3)
Issuance of long-term debt	250.0	0
Retirement of long-term debt	(310.5)	(10.0)
Change in short-term debt	(58.7)	(110.4)
Other, net	10.3	0
Cash Used in Financing Activities	(359.5)	(297.1)
Change in Cash and Cash Equivalents	(14.6)	(1.0)
Cash and Cash Equivalents at Beginning of Period	35.6	14.1
Cash and Cash Equivalents at End of Period	$ 21.0	$ 13.1