Derivative Instruments

9 Months Ended

Sep. 30, 2012

Derivative [Line Items]

Derivative Instruments

DERIVATIVE INSTRUMENTS

Commodity Derivatives -

Purpose - Alliant Energy, IPL and WPL periodically use derivative instruments for risk management purposes to mitigate exposures to fluctuations in certain commodity prices and transmission congestion costs. Refer to Note 9 for detailed discussion of Alliant Energy’s, IPL’s and WPL’s derivative instruments as of September 30, 2012 and December 31, 2011.

Notional Amounts - As of September 30, 2012, 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):

	2012	2013	2014	2015	Total
Alliant Energy
Electricity (megawatt-hours (MWhs))	1,280	3,860	2,118	876	8,134
FTRs (MWs)	16	28	—	—	44
Natural gas (dekatherms (Dths))	26,070	44,899	6,410	—	77,379
Coal (tons)	—	956	981	561	2,498
IPL
Electricity (MWhs)	786	1,978	366	—	3,130
FTRs (MWs)	8	15	—	—	23
Natural gas (Dths)	19,274	32,309	3,235	—	54,818
WPL
Electricity (MWhs)	494	1,882	1,752	876	5,004
FTRs (MWs)	8	13	—	—	21
Natural gas (Dths)	6,796	12,590	3,175	—	22,561
Coal (tons)	—	956	981	561	2,498

The notional amounts in the above table were computed by aggregating the absolute value of purchase and sale positions within commodities for each delivery year.

Financial Statement Presentation - Alliant Energy, IPL and WPL record derivative instruments at fair value each reporting date on the balance sheet as assets or liabilities. The fair values of current derivative assets were included in “Derivative assets,” non-current derivative assets were included in “Deferred charges and other,” current derivative liabilities were included in “Derivative 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
	September 30, 2012		December 31, 2011		September 30, 2012		December 31, 2011		September 30, 2012		December 31, 2011
Commodity contracts
Current derivative assets		$35.9		$12.7		$25.9		$9.2		$10.0		$3.5
Non-current derivative assets	10.6		3.0		2.2		1.4		8.4		1.6
Current derivative liabilities	37.8		55.9		17.9		24.5		19.9		31.4
Non-current derivative liabilities	19.5		22.1		4.9		9.1		14.6		13.0

Alliant Energy, IPL and WPL generally record gains and losses from IPL’s and WPL’s derivative instruments with offsets to regulatory assets or regulatory liabilities, based on their fuel and natural gas cost recovery mechanisms, as well as other specific regulatory authorizations. Gains (losses) from commodity derivative instruments not designated as hedging instruments were recorded on the Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy						IPL						WPL
	2012			2011			2012			2011			2012			2011
Three Months Ended September 30
Regulatory assets		($6.3	)		($23.8	)		($0.1	)		($13.3	)		($6.2	)		($10.5	)
Regulatory liabilities	15.8			3.7			6.9			2.2			8.9			1.5
Nine Months Ended September 30
Regulatory assets	(38.3		)	(33.1		)	(17.3		)	(18.7		)	(21.0		)	(14.4		)
Regulatory liabilities	21.3			8.6			11.3			5.4			10.0			3.2

Losses from commodity contracts during the nine months ended September 30, 2012 were primarily due to impacts of decreases in electricity and natural gas prices during the first quarter of 2012.

Credit Risk-related Contingent Features - Alliant Energy, IPL and WPL have entered into various agreements that contain credit risk-related contingent features including requirements for them to maintain certain credit ratings from each of the major credit rating agencies and/or limitations on their liability positions under the various agreements based upon their credit ratings. In the event of a downgrade in their credit ratings or if their liability positions exceed certain contractual limits, Alliant Energy, IPL or WPL may need to provide credit support in the form of letters of credit or cash collateral up to the amount of their exposure under the contracts, or may need to unwind the contracts and pay the underlying liability positions.

Certain of these agreements with credit risk-related contingency features are accounted for as derivative instruments. The aggregate fair value of all derivatives with credit risk-related contingent features that were in a net liability position on September 30, 2012 was $57.3 million, $22.8 million and $34.5 million for Alliant Energy, IPL and WPL, respectively. At September 30, 2012, Alliant Energy, IPL and WPL all had investment-grade credit ratings. However, IPL exceeded its liability position with one counterparty requiring it to post $0.3 million of cash collateral. If the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered on September 30, 2012, Alliant Energy, IPL and WPL would be required to post an additional $57.0 million, $22.5 million and $34.5 million, respectively, of credit support to their counterparties.

IPL [Member]

Derivative [Line Items]

Derivative Instruments

DERIVATIVE INSTRUMENTS

Commodity Derivatives -

Purpose - Alliant Energy, IPL and WPL periodically use derivative instruments for risk management purposes to mitigate exposures to fluctuations in certain commodity prices and transmission congestion costs. Refer to Note 9 for detailed discussion of Alliant Energy’s, IPL’s and WPL’s derivative instruments as of September 30, 2012 and December 31, 2011.

Notional Amounts - As of September 30, 2012, 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):

	2012	2013	2014	2015	Total
Alliant Energy
Electricity (megawatt-hours (MWhs))	1,280	3,860	2,118	876	8,134
FTRs (MWs)	16	28	—	—	44
Natural gas (dekatherms (Dths))	26,070	44,899	6,410	—	77,379
Coal (tons)	—	956	981	561	2,498
IPL
Electricity (MWhs)	786	1,978	366	—	3,130
FTRs (MWs)	8	15	—	—	23
Natural gas (Dths)	19,274	32,309	3,235	—	54,818
WPL
Electricity (MWhs)	494	1,882	1,752	876	5,004
FTRs (MWs)	8	13	—	—	21
Natural gas (Dths)	6,796	12,590	3,175	—	22,561
Coal (tons)	—	956	981	561	2,498

The notional amounts in the above table were computed by aggregating the absolute value of purchase and sale positions within commodities for each delivery year.

Financial Statement Presentation - Alliant Energy, IPL and WPL record derivative instruments at fair value each reporting date on the balance sheet as assets or liabilities. The fair values of current derivative assets were included in “Derivative assets,” non-current derivative assets were included in “Deferred charges and other,” current derivative liabilities were included in “Derivative 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
	September 30, 2012		December 31, 2011		September 30, 2012		December 31, 2011		September 30, 2012		December 31, 2011
Commodity contracts
Current derivative assets		$35.9		$12.7		$25.9		$9.2		$10.0		$3.5
Non-current derivative assets	10.6		3.0		2.2		1.4		8.4		1.6
Current derivative liabilities	37.8		55.9		17.9		24.5		19.9		31.4
Non-current derivative liabilities	19.5		22.1		4.9		9.1		14.6		13.0

Alliant Energy, IPL and WPL generally record gains and losses from IPL’s and WPL’s derivative instruments with offsets to regulatory assets or regulatory liabilities, based on their fuel and natural gas cost recovery mechanisms, as well as other specific regulatory authorizations. Gains (losses) from commodity derivative instruments not designated as hedging instruments were recorded on the Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy						IPL						WPL
	2012			2011			2012			2011			2012			2011
Three Months Ended September 30
Regulatory assets		($6.3	)		($23.8	)		($0.1	)		($13.3	)		($6.2	)		($10.5	)
Regulatory liabilities	15.8			3.7			6.9			2.2			8.9			1.5
Nine Months Ended September 30
Regulatory assets	(38.3		)	(33.1		)	(17.3		)	(18.7		)	(21.0		)	(14.4		)
Regulatory liabilities	21.3			8.6			11.3			5.4			10.0			3.2

Losses from commodity contracts during the nine months ended September 30, 2012 were primarily due to impacts of decreases in electricity and natural gas prices during the first quarter of 2012.

Credit Risk-related Contingent Features - Alliant Energy, IPL and WPL have entered into various agreements that contain credit risk-related contingent features including requirements for them to maintain certain credit ratings from each of the major credit rating agencies and/or limitations on their liability positions under the various agreements based upon their credit ratings. In the event of a downgrade in their credit ratings or if their liability positions exceed certain contractual limits, Alliant Energy, IPL or WPL may need to provide credit support in the form of letters of credit or cash collateral up to the amount of their exposure under the contracts, or may need to unwind the contracts and pay the underlying liability positions.

Certain of these agreements with credit risk-related contingency features are accounted for as derivative instruments. The aggregate fair value of all derivatives with credit risk-related contingent features that were in a net liability position on September 30, 2012 was $57.3 million, $22.8 million and $34.5 million for Alliant Energy, IPL and WPL, respectively. At September 30, 2012, Alliant Energy, IPL and WPL all had investment-grade credit ratings. However, IPL exceeded its liability position with one counterparty requiring it to post $0.3 million of cash collateral. If the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered on September 30, 2012, Alliant Energy, IPL and WPL would be required to post an additional $57.0 million, $22.5 million and $34.5 million, respectively, of credit support to their counterparties.

WPL [Member]

Derivative [Line Items]

Derivative Instruments

DERIVATIVE INSTRUMENTS

Commodity Derivatives -

Purpose - Alliant Energy, IPL and WPL periodically use derivative instruments for risk management purposes to mitigate exposures to fluctuations in certain commodity prices and transmission congestion costs. Refer to Note 9 for detailed discussion of Alliant Energy’s, IPL’s and WPL’s derivative instruments as of September 30, 2012 and December 31, 2011.

Notional Amounts - As of September 30, 2012, 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):

	2012	2013	2014	2015	Total
Alliant Energy
Electricity (megawatt-hours (MWhs))	1,280	3,860	2,118	876	8,134
FTRs (MWs)	16	28	—	—	44
Natural gas (dekatherms (Dths))	26,070	44,899	6,410	—	77,379
Coal (tons)	—	956	981	561	2,498
IPL
Electricity (MWhs)	786	1,978	366	—	3,130
FTRs (MWs)	8	15	—	—	23
Natural gas (Dths)	19,274	32,309	3,235	—	54,818
WPL
Electricity (MWhs)	494	1,882	1,752	876	5,004
FTRs (MWs)	8	13	—	—	21
Natural gas (Dths)	6,796	12,590	3,175	—	22,561
Coal (tons)	—	956	981	561	2,498

The notional amounts in the above table were computed by aggregating the absolute value of purchase and sale positions within commodities for each delivery year.

Financial Statement Presentation - Alliant Energy, IPL and WPL record derivative instruments at fair value each reporting date on the balance sheet as assets or liabilities. The fair values of current derivative assets were included in “Derivative assets,” non-current derivative assets were included in “Deferred charges and other,” current derivative liabilities were included in “Derivative 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
	September 30, 2012		December 31, 2011		September 30, 2012		December 31, 2011		September 30, 2012		December 31, 2011
Commodity contracts
Current derivative assets		$35.9		$12.7		$25.9		$9.2		$10.0		$3.5
Non-current derivative assets	10.6		3.0		2.2		1.4		8.4		1.6
Current derivative liabilities	37.8		55.9		17.9		24.5		19.9		31.4
Non-current derivative liabilities	19.5		22.1		4.9		9.1		14.6		13.0

Alliant Energy, IPL and WPL generally record gains and losses from IPL’s and WPL’s derivative instruments with offsets to regulatory assets or regulatory liabilities, based on their fuel and natural gas cost recovery mechanisms, as well as other specific regulatory authorizations. Gains (losses) from commodity derivative instruments not designated as hedging instruments were recorded on the Condensed Consolidated Balance Sheets as follows (in millions):

	Alliant Energy						IPL						WPL
	2012			2011			2012			2011			2012			2011
Three Months Ended September 30
Regulatory assets		($6.3	)		($23.8	)		($0.1	)		($13.3	)		($6.2	)		($10.5	)
Regulatory liabilities	15.8			3.7			6.9			2.2			8.9			1.5
Nine Months Ended September 30
Regulatory assets	(38.3		)	(33.1		)	(17.3		)	(18.7		)	(21.0		)	(14.4		)
Regulatory liabilities	21.3			8.6			11.3			5.4			10.0			3.2

Losses from commodity contracts during the nine months ended September 30, 2012 were primarily due to impacts of decreases in electricity and natural gas prices during the first quarter of 2012.

Credit Risk-related Contingent Features - Alliant Energy, IPL and WPL have entered into various agreements that contain credit risk-related contingent features including requirements for them to maintain certain credit ratings from each of the major credit rating agencies and/or limitations on their liability positions under the various agreements based upon their credit ratings. In the event of a downgrade in their credit ratings or if their liability positions exceed certain contractual limits, Alliant Energy, IPL or WPL may need to provide credit support in the form of letters of credit or cash collateral up to the amount of their exposure under the contracts, or may need to unwind the contracts and pay the underlying liability positions.

Certain of these agreements with credit risk-related contingency features are accounted for as derivative instruments. The aggregate fair value of all derivatives with credit risk-related contingent features that were in a net liability position on September 30, 2012 was $57.3 million, $22.8 million and $34.5 million for Alliant Energy, IPL and WPL, respectively. At September 30, 2012, Alliant Energy, IPL and WPL all had investment-grade credit ratings. However, IPL exceeded its liability position with one counterparty requiring it to post $0.3 million of cash collateral. If the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered on September 30, 2012, Alliant Energy, IPL and WPL would be required to post an additional $57.0 million, $22.5 million and $34.5 million, respectively, of credit support to their counterparties.