Derivative Instruments (Tables)

6 Months Ended

Jun. 30, 2013

Derivative [Line Items]

Notional Amounts Of Derivative Instruments

As of June 30, 2013, notional amounts by delivery year related to outstanding swap contracts, option contracts, physical forward contracts, FTRs and coal contracts that were accounted for as commodity derivative instruments were as follows (units in thousands):

	2013	2014	2015	2016	2017	2018	Total
Alliant Energy
Electricity (megawatt-hours (MWhs))	2,620	4,801	2,190	1,318	1,314	1,314	13,557
FTRs (MWs)	26	22	—	—	—	—	48
Natural gas (dekatherms (Dths))	52,111	19,846	2,031	455	—	—	74,443
Coal (tons)	448	981	562	—	—	—	1,991
IPL
Electricity (MWhs)	1,302	1,099	—	—	—	—	2,401
FTRs (MWs)	16	14	—	—	—	—	30
Natural gas (Dths)	40,455	13,386	1,581	455	—	—	55,877
WPL
Electricity (MWhs)	1,318	3,702	2,190	1,318	1,314	1,314	11,156
FTRs (MWs)	10	8	—	—	—	—	18
Natural gas (Dths)	11,656	6,460	450	—	—	—	18,566
Coal (tons)	448	981	562	—	—	—	1,991

Fair Value Of Financial Instruments

The fair values of current derivative assets were included in “Other current assets,” non-current derivative assets were included in “Deferred charges and other,” current derivative liabilities were included in “Other current liabilities” and non-current derivative liabilities were included in “Other long-term liabilities and deferred credits” on the Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy				IPL				WPL
Commodity contracts	June 30, 2013		December 31, 2012		June 30, 2013		December 31, 2012		June 30, 2013		December 31, 2012
Current derivative assets		$51.1		$23.5		$44.4		$17.0		$6.7		$6.5
Non-current derivative assets	9.4		2.7		0.7		0.5		8.7		2.2
Current derivative liabilities	21.8		31.1		8.4		14.1		13.4		17.0
Non-current derivative liabilities	15.3		9.3		1.3		2.0		14.0		7.3

Gains And Losses From Derivative Instruments Not Designated As Hedging Instruments

Changes in unrealized gains (losses) from commodity derivative instruments not designated as hedging instruments were recorded with offsets to regulatory assets or regulatory liabilities on the Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy						IPL						WPL
	2013			2012			2013			2012			2013			2012
Three Months Ended June 30
Regulatory assets		($25.9	)		$7.7			($6.9	)		$5.0			($19.0	)		$2.7
Regulatory liabilities	1.2			4.1			(2.5		)	4.4			3.7			(0.3		)
Six Months Ended June 30
Regulatory assets	(16.4		)	(32.0		)	(4.2		)	(17.2		)	(12.2		)	(14.8		)
Regulatory liabilities	17.6			5.5			6.3			4.4			11.3			1.1

Balance Sheet Offsetting

Alliant Energy, IPL and WPL do not net the fair value amounts of derivative instruments subject to a master netting arrangement by counterparty on the Condensed Consolidated Balance Sheets. Alliant Energy, IPL and WPL also do not offset fair value amounts recognized for the right to reclaim cash collateral (receivable) or the obligation to return cash collateral (payable) against fair value amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement. However, if Alliant Energy, IPL and WPL did net the fair value amounts of derivative instruments and related cash collateral by counterparty, derivative assets and derivative liabilities related to commodity contracts would have been presented on their Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy				IPL				WPL
	Gross				Gross				Gross
	(as reported)		Net		(as reported)		Net		(as reported)		Net
June 30, 2013
Derivative assets		$60.5		$46.3		$45.1		$43.4		$15.4		$2.9
Derivative liabilities	37.1		22.9		9.7		8.0		27.4		14.9
December 31, 2012
Derivative assets	26.2		19.3		17.5		14.5		8.7		4.8
Derivative liabilities	40.4		33.0		16.1		12.6		24.3		20.4

IPL [Member]

Derivative [Line Items]

Notional Amounts Of Derivative Instruments

As of June 30, 2013, notional amounts by delivery year related to outstanding swap contracts, option contracts, physical forward contracts, FTRs and coal contracts that were accounted for as commodity derivative instruments were as follows (units in thousands):

	2013	2014	2015	2016	2017	2018	Total
Alliant Energy
Electricity (megawatt-hours (MWhs))	2,620	4,801	2,190	1,318	1,314	1,314	13,557
FTRs (MWs)	26	22	—	—	—	—	48
Natural gas (dekatherms (Dths))	52,111	19,846	2,031	455	—	—	74,443
Coal (tons)	448	981	562	—	—	—	1,991
IPL
Electricity (MWhs)	1,302	1,099	—	—	—	—	2,401
FTRs (MWs)	16	14	—	—	—	—	30
Natural gas (Dths)	40,455	13,386	1,581	455	—	—	55,877
WPL
Electricity (MWhs)	1,318	3,702	2,190	1,318	1,314	1,314	11,156
FTRs (MWs)	10	8	—	—	—	—	18
Natural gas (Dths)	11,656	6,460	450	—	—	—	18,566
Coal (tons)	448	981	562	—	—	—	1,991

Fair Value Of Financial Instruments

The fair values of current derivative assets were included in “Other current assets,” non-current derivative assets were included in “Deferred charges and other,” current derivative liabilities were included in “Other current liabilities” and non-current derivative liabilities were included in “Other long-term liabilities and deferred credits” on the Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy				IPL				WPL
Commodity contracts	June 30, 2013		December 31, 2012		June 30, 2013		December 31, 2012		June 30, 2013		December 31, 2012
Current derivative assets		$51.1		$23.5		$44.4		$17.0		$6.7		$6.5
Non-current derivative assets	9.4		2.7		0.7		0.5		8.7		2.2
Current derivative liabilities	21.8		31.1		8.4		14.1		13.4		17.0
Non-current derivative liabilities	15.3		9.3		1.3		2.0		14.0		7.3

Gains And Losses From Derivative Instruments Not Designated As Hedging Instruments

Changes in unrealized gains (losses) from commodity derivative instruments not designated as hedging instruments were recorded with offsets to regulatory assets or regulatory liabilities on the Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy						IPL						WPL
	2013			2012			2013			2012			2013			2012
Three Months Ended June 30
Regulatory assets		($25.9	)		$7.7			($6.9	)		$5.0			($19.0	)		$2.7
Regulatory liabilities	1.2			4.1			(2.5		)	4.4			3.7			(0.3		)
Six Months Ended June 30
Regulatory assets	(16.4		)	(32.0		)	(4.2		)	(17.2		)	(12.2		)	(14.8		)
Regulatory liabilities	17.6			5.5			6.3			4.4			11.3			1.1

Balance Sheet Offsetting

Alliant Energy, IPL and WPL do not net the fair value amounts of derivative instruments subject to a master netting arrangement by counterparty on the Condensed Consolidated Balance Sheets. Alliant Energy, IPL and WPL also do not offset fair value amounts recognized for the right to reclaim cash collateral (receivable) or the obligation to return cash collateral (payable) against fair value amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement. However, if Alliant Energy, IPL and WPL did net the fair value amounts of derivative instruments and related cash collateral by counterparty, derivative assets and derivative liabilities related to commodity contracts would have been presented on their Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy				IPL				WPL
	Gross				Gross				Gross
	(as reported)		Net		(as reported)		Net		(as reported)		Net
June 30, 2013
Derivative assets		$60.5		$46.3		$45.1		$43.4		$15.4		$2.9
Derivative liabilities	37.1		22.9		9.7		8.0		27.4		14.9
December 31, 2012
Derivative assets	26.2		19.3		17.5		14.5		8.7		4.8
Derivative liabilities	40.4		33.0		16.1		12.6		24.3		20.4

WPL [Member]

Derivative [Line Items]

Notional Amounts Of Derivative Instruments

As of June 30, 2013, notional amounts by delivery year related to outstanding swap contracts, option contracts, physical forward contracts, FTRs and coal contracts that were accounted for as commodity derivative instruments were as follows (units in thousands):

	2013	2014	2015	2016	2017	2018	Total
Alliant Energy
Electricity (megawatt-hours (MWhs))	2,620	4,801	2,190	1,318	1,314	1,314	13,557
FTRs (MWs)	26	22	—	—	—	—	48
Natural gas (dekatherms (Dths))	52,111	19,846	2,031	455	—	—	74,443
Coal (tons)	448	981	562	—	—	—	1,991
IPL
Electricity (MWhs)	1,302	1,099	—	—	—	—	2,401
FTRs (MWs)	16	14	—	—	—	—	30
Natural gas (Dths)	40,455	13,386	1,581	455	—	—	55,877
WPL
Electricity (MWhs)	1,318	3,702	2,190	1,318	1,314	1,314	11,156
FTRs (MWs)	10	8	—	—	—	—	18
Natural gas (Dths)	11,656	6,460	450	—	—	—	18,566
Coal (tons)	448	981	562	—	—	—	1,991

Fair Value Of Financial Instruments

The fair values of current derivative assets were included in “Other current assets,” non-current derivative assets were included in “Deferred charges and other,” current derivative liabilities were included in “Other current liabilities” and non-current derivative liabilities were included in “Other long-term liabilities and deferred credits” on the Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy				IPL				WPL
Commodity contracts	June 30, 2013		December 31, 2012		June 30, 2013		December 31, 2012		June 30, 2013		December 31, 2012
Current derivative assets		$51.1		$23.5		$44.4		$17.0		$6.7		$6.5
Non-current derivative assets	9.4		2.7		0.7		0.5		8.7		2.2
Current derivative liabilities	21.8		31.1		8.4		14.1		13.4		17.0
Non-current derivative liabilities	15.3		9.3		1.3		2.0		14.0		7.3

Gains And Losses From Derivative Instruments Not Designated As Hedging Instruments

Changes in unrealized gains (losses) from commodity derivative instruments not designated as hedging instruments were recorded with offsets to regulatory assets or regulatory liabilities on the Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy						IPL						WPL
	2013			2012			2013			2012			2013			2012
Three Months Ended June 30
Regulatory assets		($25.9	)		$7.7			($6.9	)		$5.0			($19.0	)		$2.7
Regulatory liabilities	1.2			4.1			(2.5		)	4.4			3.7			(0.3		)
Six Months Ended June 30
Regulatory assets	(16.4		)	(32.0		)	(4.2		)	(17.2		)	(12.2		)	(14.8		)
Regulatory liabilities	17.6			5.5			6.3			4.4			11.3			1.1

Balance Sheet Offsetting

Alliant Energy, IPL and WPL do not net the fair value amounts of derivative instruments subject to a master netting arrangement by counterparty on the Condensed Consolidated Balance Sheets. Alliant Energy, IPL and WPL also do not offset fair value amounts recognized for the right to reclaim cash collateral (receivable) or the obligation to return cash collateral (payable) against fair value amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement. However, if Alliant Energy, IPL and WPL did net the fair value amounts of derivative instruments and related cash collateral by counterparty, derivative assets and derivative liabilities related to commodity contracts would have been presented on their Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy				IPL				WPL
	Gross				Gross				Gross
	(as reported)		Net		(as reported)		Net		(as reported)		Net
June 30, 2013
Derivative assets		$60.5		$46.3		$45.1		$43.4		$15.4		$2.9
Derivative liabilities	37.1		22.9		9.7		8.0		27.4		14.9
December 31, 2012
Derivative assets	26.2		19.3		17.5		14.5		8.7		4.8
Derivative liabilities	40.4		33.0		16.1		12.6		24.3		20.4