XML 157 R30.htm IDEA: XBRL DOCUMENT v2.4.0.8

Investments (Tables)

6 Months Ended

Jun. 30, 2013

Schedule of Investments [Line Items]

Unconsolidated Equity Investments

Equity (income) loss from Alliant Energy’s and WPL’s unconsolidated investments accounted for under the equity method of accounting for the three and six months ended June 30 was as follows (in millions):

	Alliant Energy																WPL
	Three Months								Six Months								Three Months								Six Months
	2013				2012				2013				2012				2013				2012				2013				2012
American Transmission Company LLC (ATC)		($10.6	)			($10.3	)			($20.9	)			($20.2	)			($10.6	)			($10.3	)			($20.9	)			($20.2	)
Other	(0.3		)		(0.3		)		(0.7		)		0.2				(0.2		)		(0.3		)		(0.7		)		(0.5		)
		($10.9	)			($10.6	)			($21.6	)			($20.0	)			($10.8	)			($10.6	)			($21.6	)			($20.7	)

Summary Financial Information

Summary financial information from the unaudited financial statements of ATC for the three and six months ended June 30 was as follows (in millions):

	Three Months								Six Months
	2013				2012				2013				2012
Operating revenues		$152.2				$152.1				$303.9				$299.8
Operating income	82.2				80.4				164.2				158.5
Net income	61.3				59.3				121.8				117.4

WPL [Member]

Schedule of Investments [Line Items]

Unconsolidated Equity Investments

Equity (income) loss from Alliant Energy’s and WPL’s unconsolidated investments accounted for under the equity method of accounting for the three and six months ended June 30 was as follows (in millions):

	Alliant Energy																WPL
	Three Months								Six Months								Three Months								Six Months
	2013				2012				2013				2012				2013				2012				2013				2012
American Transmission Company LLC (ATC)		($10.6	)			($10.3	)			($20.9	)			($20.2	)			($10.6	)			($10.3	)			($20.9	)			($20.2	)
Other	(0.3		)		(0.3		)		(0.7		)		0.2				(0.2		)		(0.3		)		(0.7		)		(0.5		)
		($10.9	)			($10.6	)			($21.6	)			($20.0	)			($10.8	)			($10.6	)			($21.6	)			($20.7	)

Summary Financial Information

Summary financial information from the unaudited financial statements of ATC for the three and six months ended June 30 was as follows (in millions):

	Three Months								Six Months
	2013				2012				2013				2012
Operating revenues		$152.2				$152.1				$303.9				$299.8
Operating income	82.2				80.4				164.2				158.5
Net income	61.3				59.3				121.8				117.4

X

- Details

Name:	invest_InvestmentLineItems
Namespace Prefix:	invest_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Schedule of Summary Financial Information [Table Text Block]

+ References

No definition available.

+ Details

Name:	lnt_ScheduleOfSummaryFinancialInformationTableTextBlock
Namespace Prefix:	lnt_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of equity method investments in common stock. The disclosure may include: (a) the name of each investee or group of investments for which combined disclosure is appropriate, (2) the percentage ownership of common stock, (3) the difference, if any, between the carrying amount of an investment and the value of the underlying equity in the net assets and the accounting treatment of difference, if any, and (4) the aggregate value of each identified investment based on its quoted market price, if available.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571



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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a, b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_EquityMethodInvestmentsTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration