Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating Activities
Net income	$ 526.2	$ 456.5	$ 382.4
Reconciliation to cash
Depreciation and amortization	336.4	317.4	346.9
Amortization of gain	0	(198.4)	(230.7)
Deferred income taxes and investment tax credits, net	430.6	104.9	187.4
Deferred revenue	3.5	100.8	201.7
Contributions to qualified benefit plans	(277.4)	0	(289.3)
Change in -
Accounts receivable and accrued revenues	30.1	(50.4)	111.1
Inventories	(2.9)	(1.0)	(34.6)
Other current assets	(20.5)	14.1	24.8
Accounts payable	11.8	21.3	(119.1)
Accrued income taxes, net	(87.4)	(42.7)	43.4
Deferred costs, net	25.9	25.9	46.2
Other current liabilities	44.1	22.0	(11.7)
Other, net	(27.0)	40.0	(29.6)
Cash Provided by Operating Activities	993.4	810.4	628.9
Investing Activities
Capital expenditures	(830.8)	(798.2)	(814.6)
Investment in transmission affiliate	(6.6)	(5.2)	(25.9)
Proceeds from asset sales	41.5	68.7	16.8
Change in restricted cash	(37.2)	186.2	192.0
Other, net	(59.4)	(85.0)	(104.4)
Cash Used in Investing Activities	(892.5)	(633.5)	(736.1)
Financing Activities
Exercise of stock options	54.4	90.9	17.0
Purchase of common stock	(193.9)	(156.6)	(29.6)
Dividends paid on common stock	(242.0)	(187.0)	(157.8)
Issuance of long-term debt	720.0	530.0	261.5
Retirement and repurchase of long-term debt	(466.6)	(291.7)	(221.1)
Change in short-term debt	12.0	(167.2)	222.8
Other, net	4.8	9.0	2.9
Cash (Used in) Provided by Financing Activities	(111.3)	(172.6)	95.7
Change in Cash and Cash Equivalents	(10.4)	4.3	(11.5)
Cash and Cash Equivalents at Beginning of Year	24.5	20.2	31.7
Cash and Cash Equivalents at End of Year	$ 14.1	$ 24.5	$ 20.2

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).