CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating Activities
Net income	$ 245.1	$ 222.4
Adjustments to reconcile net income to net cash provided by operating activities
Goodwill impairment loss	6.7	0
Depreciation and amortization expense	217.5	196.0
Recoveries and refunds of regulatory assets and liabilities	46.5	35.2
Net unrealized gains on energy contracts	(27.9)	(17.3)
Bad debt expense	39.6	22.2
Pension and other postretirement expense	15.8	47.4
Pension and other postretirement contributions	(95.4)	(65.0)
Deferred income taxes and investment tax credits	53.5	131.7
Gain on sale of UPPCO	(86.5)	0
Equity income, net of dividends	(15.4)	(14.1)
Termination of tolling agreement with Fox Energy Company LLC	0	(50.0)
Other	17.5	25.5
Changes in working capital
Accounts receivable and accrued unbilled revenues	257.9	80.6
Inventories	(158.5)	(70.1)
Other current assets	60.1	(31.4)
Accounts payable	(28.0)	21.7
Other current liabilities	69.4	(22.6)
Net cash provided by operating activities	617.9	512.2
Investing Activities
Capital expenditures	(590.9)	(474.7)
Proceeds from sale of UPPCO	332.2	0
Capital contributions to equity method investments	(14.6)	(10.2)
Rabbi trust funding related to potential change in control	(113.0)	0
Acquisition of Fox Energy Company LLC	0	(391.6)
Acquisitions at IES	0	(12.4)
Grant received related to Crane Creek wind project	0	69.0
Other	(2.4)	0.1
Net cash used for investing activities	(388.7)	(819.8)
Financing Activities
Short-term debt, net	66.5	(294.4)
Borrowing on term credit facility	0	200.0
Issuance of long-term debt	0	724.0
Repayment of long-term debt	(100.0)	(187.0)
Proceeds from stock option exercises	20.0	38.5
Shares purchased for stock-based compensation	(45.1)	(2.0)
Payment of dividends
Preferred stock of subsidiary	(2.3)	(2.3)
Common stock	(162.3)	(151.6)
Other	(12.2)	(18.9)
Net cash (used for) provided by financing activities	(235.4)	306.3
Net change in cash and cash equivalents	(6.2)	(1.3)
Cash and cash equivalents at beginning of period	22.3	27.4
Cash and cash equivalents at end of period	16.1	26.1
Supplemental Cash Flow Information
Cash paid for interest	88.1	60.7
Cash received for income taxes	$ (6.5)	$ (2.6)