Fossil Fueled Energy Generating Units Capacity

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- Definition

Carrying amount as of the balance sheet date of long-lived, depreciable Alliant Energy Corporate Services, Inc. and other plant.

+ References

No definition available.

+ Details

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- Definition

Amount of accumulated interest costs capitalized as part of property, plant and equipment cost basis.

+ References

No definition available.

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- Definition

The increase (decrease) during the reporting period in other noncurrent operating assets not separately disclosed in the statement of cash flows.

+ References

No definition available.

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- Definition

The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

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- Definition

Total increase in earnings in the period representing the cost of equity (based on assumed rate of return) and/or borrowed funds (based on interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 360

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6500269&loc=d3e45485-110386

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 340

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44278-110382

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- Definition

Period end amount of construction work in progress in public utility.

+ References

No definition available.

+ Details

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Property, Plant and Equipment (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Apr. 30, 2015
Property, Plant and Equipment [Line Items]
Allowance for funds used during construction	$ 6.8	$ 9.1
IPL [Member]
Property, Plant and Equipment [Line Items]
Allowance for funds used during construction	5.3	6.0
Edgewater Unit 5 [Member] \| Alliant Energy and WPL [Member]
Property, Plant and Equipment [Line Items]
Construction work in progress	110
Allowance for funds used during construction	4.0
Marshalltown [Member]
Property, Plant and Equipment [Line Items]
Fossil-fueled EGU capacity (in megawatts)	650
Marshalltown [Member] \| Alliant Energy and IPL [Member]
Property, Plant and Equipment [Line Items]
Construction work in progress	248
Allowance for funds used during construction	7.0
Customer Billing And Information System [Member]
Property, Plant and Equipment [Line Items]
Capitalized expenditures	71
Capitalized interest	2
Subsequent Event [Member] \| Gas distribution assets [Member] \| IPL [Member]
Property, Plant and Equipment [Line Items]
Expected proceeds from asset sales			11
Expected receipt of promissory note			$ 2