Investments (Tables)

3 Months Ended

Mar. 31, 2014

Schedule of Investments [Line Items]

Unconsolidated Equity Investments

Equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three months ended March 31 was as follows (in millions):

	Alliant Energy						WPL
	2014			2013			2014			2013
ATC		($11.2	)		($10.3	)		($11.2	)		($10.3	)
Other	(0.2		)	(0.4		)	(0.2		)	(0.5		)
		($11.4	)		($10.7	)		($11.4	)		($10.8	)

WPL [Member]

Schedule of Investments [Line Items]

Unconsolidated Equity Investments

Equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three months ended March 31 was as follows (in millions):

	Alliant Energy						WPL
	2014			2013			2014			2013
ATC		($11.2	)		($10.3	)		($11.2	)		($10.3	)
Other	(0.2		)	(0.4		)	(0.2		)	(0.5		)
		($11.4	)		($10.7	)		($11.4	)		($10.8	)