Derivative Instruments (Tables)

6 Months Ended

Jun. 30, 2015

Derivative Instruments [Line Items]

Notional Amounts Of Derivative Instruments

As of June 30, 2015, gross 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):

	2015	2016	2017	2018	Total
Alliant Energy
Electricity (MWhs)	2,432	3,240	1,314	1,314	8,300
FTRs (MWhs)	11,952	9,961	—	—	21,913
Natural gas (Dths)	36,167	34,330	9,079	126	79,702
Coal (tons)	897	2,260	1,073	1,113	5,343
IPL
Electricity (MWhs)	1,100	809	—	—	1,909
FTRs (MWhs)	6,664	5,696	—	—	12,360
Natural gas (Dths)	23,343	18,103	2,886	126	44,458
Coal (tons)	189	830	274	387	1,680
WPL
Electricity (MWhs)	1,332	2,431	1,314	1,314	6,391
FTRs (MWhs)	5,288	4,265	—	—	9,553
Natural gas (Dths)	12,824	16,227	6,193	—	35,244
Coal (tons)	708	1,430	799	726	3,663

Fair Value Of Financial Instruments

The fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions):

	Alliant Energy				IPL				WPL
Commodity contracts	June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014
Current derivative assets		$34.2		$30.5		$30.0		$27.4		$4.2		$3.1
Non-current derivative assets	0.8		8.1		0.7		0.6		0.1		7.5
Current derivative liabilities	27.1		28.1		13.8		16.4		13.3		11.7
Non-current derivative liabilities	19.9		9.5		6.9		3.1		13.0		6.4

Gains And Losses From Derivative Instruments

Changes in unrealized gains (losses) from commodity derivative instruments were recorded with offsets to regulatory assets or regulatory liabilities on the balance sheets as follows (in millions):

	Alliant Energy						IPL						WPL
	2015			2014			2015			2014			2015			2014
Three Months Ended June 30
Regulatory assets		($21.2	)		($4.6	)		($12.1	)		($4.1	)		($9.1	)		($0.5	)
Regulatory liabilities	(4.6		)	21.3			3.6			3.8			(8.2		)	17.5
Six Months Ended June 30
Regulatory assets	(42.1		)	5.5			(23.8		)	1.4			(18.3		)	4.1
Regulatory liabilities	(2.4		)	69.4			2.2			15.9			(4.6		)	53.5

Credit Risk-related Contingent Features

The aggregate fair value of all derivative instruments with credit risk-related contingent features in a net liability position, as well as amounts that would be required to be posted as credit support to counterparties by Alliant Energy, IPL or WPL if the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered, were as follows (in millions):

	Alliant Energy				IPL				WPL
	June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014
Aggregate fair value		$47.0		$37.6		$20.7		$19.5		$26.3		$18.1
Credit support to be posted if triggered	46.9		37.4		20.7		19.5		26.2		17.9

Balance Sheet Offsetting

The fair value amounts of derivative instruments subject to a master netting arrangement are not netted by counterparty on the balance sheets. However, if the fair value amounts of derivative instruments by counterparty were netted, derivative assets and derivative liabilities related to commodity contracts would have been presented on the balance sheets as follows (in millions):

	Alliant Energy				IPL				WPL
	Gross				Gross				Gross
	(as reported)		Net		(as reported)		Net		(as reported)		Net
June 30, 2015
Derivative assets		$35.0		$32.0		$30.7		$29.3		$4.3		$2.7
Derivative liabilities	47.0		44.0		20.7		19.3		26.3		24.7
December 31, 2014
Derivative assets	38.6		33.0		28.0		24.7		10.6		8.3
Derivative liabilities	37.6		32.0		19.5		16.2		18.1		15.8

IPL [Member]

Derivative Instruments [Line Items]

Notional Amounts Of Derivative Instruments

As of June 30, 2015, gross 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):

	2015	2016	2017	2018	Total
Alliant Energy
Electricity (MWhs)	2,432	3,240	1,314	1,314	8,300
FTRs (MWhs)	11,952	9,961	—	—	21,913
Natural gas (Dths)	36,167	34,330	9,079	126	79,702
Coal (tons)	897	2,260	1,073	1,113	5,343
IPL
Electricity (MWhs)	1,100	809	—	—	1,909
FTRs (MWhs)	6,664	5,696	—	—	12,360
Natural gas (Dths)	23,343	18,103	2,886	126	44,458
Coal (tons)	189	830	274	387	1,680
WPL
Electricity (MWhs)	1,332	2,431	1,314	1,314	6,391
FTRs (MWhs)	5,288	4,265	—	—	9,553
Natural gas (Dths)	12,824	16,227	6,193	—	35,244
Coal (tons)	708	1,430	799	726	3,663

Fair Value Of Financial Instruments

The fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions):

	Alliant Energy				IPL				WPL
Commodity contracts	June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014
Current derivative assets		$34.2		$30.5		$30.0		$27.4		$4.2		$3.1
Non-current derivative assets	0.8		8.1		0.7		0.6		0.1		7.5
Current derivative liabilities	27.1		28.1		13.8		16.4		13.3		11.7
Non-current derivative liabilities	19.9		9.5		6.9		3.1		13.0		6.4

Gains And Losses From Derivative Instruments

Changes in unrealized gains (losses) from commodity derivative instruments were recorded with offsets to regulatory assets or regulatory liabilities on the balance sheets as follows (in millions):

	Alliant Energy						IPL						WPL
	2015			2014			2015			2014			2015			2014
Three Months Ended June 30
Regulatory assets		($21.2	)		($4.6	)		($12.1	)		($4.1	)		($9.1	)		($0.5	)
Regulatory liabilities	(4.6		)	21.3			3.6			3.8			(8.2		)	17.5
Six Months Ended June 30
Regulatory assets	(42.1		)	5.5			(23.8		)	1.4			(18.3		)	4.1
Regulatory liabilities	(2.4		)	69.4			2.2			15.9			(4.6		)	53.5

Credit Risk-related Contingent Features

The aggregate fair value of all derivative instruments with credit risk-related contingent features in a net liability position, as well as amounts that would be required to be posted as credit support to counterparties by Alliant Energy, IPL or WPL if the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered, were as follows (in millions):

	Alliant Energy				IPL				WPL
	June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014
Aggregate fair value		$47.0		$37.6		$20.7		$19.5		$26.3		$18.1
Credit support to be posted if triggered	46.9		37.4		20.7		19.5		26.2		17.9

Balance Sheet Offsetting

The fair value amounts of derivative instruments subject to a master netting arrangement are not netted by counterparty on the balance sheets. However, if the fair value amounts of derivative instruments by counterparty were netted, derivative assets and derivative liabilities related to commodity contracts would have been presented on the balance sheets as follows (in millions):

	Alliant Energy				IPL				WPL
	Gross				Gross				Gross
	(as reported)		Net		(as reported)		Net		(as reported)		Net
June 30, 2015
Derivative assets		$35.0		$32.0		$30.7		$29.3		$4.3		$2.7
Derivative liabilities	47.0		44.0		20.7		19.3		26.3		24.7
December 31, 2014
Derivative assets	38.6		33.0		28.0		24.7		10.6		8.3
Derivative liabilities	37.6		32.0		19.5		16.2		18.1		15.8

WPL [Member]

Derivative Instruments [Line Items]

Notional Amounts Of Derivative Instruments

As of June 30, 2015, gross 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):

	2015	2016	2017	2018	Total
Alliant Energy
Electricity (MWhs)	2,432	3,240	1,314	1,314	8,300
FTRs (MWhs)	11,952	9,961	—	—	21,913
Natural gas (Dths)	36,167	34,330	9,079	126	79,702
Coal (tons)	897	2,260	1,073	1,113	5,343
IPL
Electricity (MWhs)	1,100	809	—	—	1,909
FTRs (MWhs)	6,664	5,696	—	—	12,360
Natural gas (Dths)	23,343	18,103	2,886	126	44,458
Coal (tons)	189	830	274	387	1,680
WPL
Electricity (MWhs)	1,332	2,431	1,314	1,314	6,391
FTRs (MWhs)	5,288	4,265	—	—	9,553
Natural gas (Dths)	12,824	16,227	6,193	—	35,244
Coal (tons)	708	1,430	799	726	3,663

Fair Value Of Financial Instruments

The fair values of current derivative assets are included in “Other current assets,” non-current derivative assets are included in “Deferred charges and other,” current derivative liabilities are included in “Other current liabilities” and non-current derivative liabilities are included in “Other liabilities” on the balance sheets as follows (in millions):

	Alliant Energy				IPL				WPL
Commodity contracts	June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014
Current derivative assets		$34.2		$30.5		$30.0		$27.4		$4.2		$3.1
Non-current derivative assets	0.8		8.1		0.7		0.6		0.1		7.5
Current derivative liabilities	27.1		28.1		13.8		16.4		13.3		11.7
Non-current derivative liabilities	19.9		9.5		6.9		3.1		13.0		6.4

Gains And Losses From Derivative Instruments

Changes in unrealized gains (losses) from commodity derivative instruments were recorded with offsets to regulatory assets or regulatory liabilities on the balance sheets as follows (in millions):

	Alliant Energy						IPL						WPL
	2015			2014			2015			2014			2015			2014
Three Months Ended June 30
Regulatory assets		($21.2	)		($4.6	)		($12.1	)		($4.1	)		($9.1	)		($0.5	)
Regulatory liabilities	(4.6		)	21.3			3.6			3.8			(8.2		)	17.5
Six Months Ended June 30
Regulatory assets	(42.1		)	5.5			(23.8		)	1.4			(18.3		)	4.1
Regulatory liabilities	(2.4		)	69.4			2.2			15.9			(4.6		)	53.5

Credit Risk-related Contingent Features

The aggregate fair value of all derivative instruments with credit risk-related contingent features in a net liability position, as well as amounts that would be required to be posted as credit support to counterparties by Alliant Energy, IPL or WPL if the most restrictive credit risk-related contingent features for derivative agreements in a net liability position were triggered, were as follows (in millions):

	Alliant Energy				IPL				WPL
	June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014		June 30, 2015		December 31, 2014
Aggregate fair value		$47.0		$37.6		$20.7		$19.5		$26.3		$18.1
Credit support to be posted if triggered	46.9		37.4		20.7		19.5		26.2		17.9

Balance Sheet Offsetting

The fair value amounts of derivative instruments subject to a master netting arrangement are not netted by counterparty on the balance sheets. However, if the fair value amounts of derivative instruments by counterparty were netted, derivative assets and derivative liabilities related to commodity contracts would have been presented on the balance sheets as follows (in millions):

	Alliant Energy				IPL				WPL
	Gross				Gross				Gross
	(as reported)		Net		(as reported)		Net		(as reported)		Net
June 30, 2015
Derivative assets		$35.0		$32.0		$30.7		$29.3		$4.3		$2.7
Derivative liabilities	47.0		44.0		20.7		19.3		26.3		24.7
December 31, 2014
Derivative assets	38.6		33.0		28.0		24.7		10.6		8.3
Derivative liabilities	37.6		32.0		19.5		16.2		18.1		15.8