Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Average Rates of Depreciation

The average rates of depreciation for electric, gas and other properties, consistent with current rate-making practices, were as follows:

	IPL			WPL
	2015	2014	2013	2015	2014	2013
Electric - generation	3.6%	3.6%	3.6%	3.2%	3.2%	3.3%
Electric - distribution	2.4%	2.5%	2.5%	2.7%	2.7%	2.7%
Electric - other	4.0%	4.0%	4.0%	4.5%	5.9%	5.0%
Gas	3.2%	3.3%	3.4%	2.5%	2.5%	2.5%
Other	3.9%	4.3%	4.7%	6.0%	6.0%	5.1%

Schedule of Allowance for Funds Used During Construction Rate

The AFUDC rates, computed in accordance with the prescribed regulatory formula, were as follows:

	2015	2014	2013
IPL (Marshalltown CWIP) (a)	7.9%	8.0%	—%
IPL (other CWIP)	7.7%	7.8%	8.2%
WPL (retail jurisdiction)	8.2%	8.2%	8.2%
WPL (wholesale jurisdiction)	7.9%	4.1%	4.5%

(a) In 2013, the IUB issued an order establishing rate-making principles for Marshalltown that requires a 10.3% return on common equity for the calculation of AFUDC related to the construction of such facility.

Schedule of New Accounting Standards and Changes in Accounting Principles

The following financial statement line items were affected by these changes (in millions):

Alliant Energy	Originally		Effect of New			As
Balance Sheet as of December 31, 2014	Reported		Accounting Standard			Adjusted
Deferred charges and other		$43.9		($22.4	)		$21.5
Total other assets	1,759.5		(22.4		)	1,737.1
Total assets	12,085.9		(22.4		)	12,063.5
Long-term debt, net (excluding current portion)	3,606.7		(22.4		)	3,584.3
Total liabilities and equity	12,085.9		(22.4		)	12,063.5

IPL	2014									2013
Income Statements				Effect of Change in									Effect of Change in
	Originally			Method of Calculating			As			Originally			Method of Calculating			As
	Reported			Income Taxes			Adjusted			Reported			Income Taxes			Adjusted
Income tax benefit		($51.7	)		$2.8			($48.9	)		($37.9	)		$1.6			($36.3	)
Net income	194.6			(2.8		)	191.8			189.9			(1.6		)	188.3
Earnings available for common stock	184.4			(2.8		)	181.6			173.6			(1.6		)	172.0

IPL			Effect of New			Effect of Change in
Balance Sheets	Originally		Accounting			Method of Calculating			As
December 31, 2014	Reported		Standard			Income Taxes			Adjusted
Deferred tax assets		$104.9		$—			($0.9	)		$104.0
Total current assets	556.1		—			(0.9		)	555.2
Deferred charges and other	12.7		(10.7		)	—			2.0
Total other assets	1,331.9		(10.7		)	—			1,321.2
Total assets	6,461.8		(10.7		)	(0.9		)	6,450.2
Long-term debt, net (excluding current portion)	1,618.7		(10.7		)	—			1,608.0
Deferred tax liabilities	1,341.4		—			28.9			1,370.3
Total other liabilities	2,123.1		—			28.9			2,152.0
Retained earnings	537.9		—			(29.8		)	508.1
Total IPL common equity	1,814.1		—			(29.8		)	1,784.3
Total equity	2,014.1		—			(29.8		)	1,984.3
Total liabilities and equity	6,461.8		(10.7		)	(0.9		)	6,450.2
January 1, 2014
Retained earnings	493.5		—			(31.6		)	461.9
January 1, 2013
Retained earnings	448.0		—			(32.8		)	415.2

IPL	2014									2013
Cash Flows				Effect of Change in									Effect of Change in
	Originally			Method of Calculating			As			Originally			Method of Calculating			As
	Reported			Income Taxes			Adjusted			Reported			Income Taxes			Adjusted
Cash flows from operating activities:
Net income		$194.6			($2.8	)		$191.8			$189.9			($1.6	)		$188.3
Adjustments to reconcile net income to net cash flows from operating activities:
Deferred tax expense (benefit) and investment tax credits	(9.7		)	(1.8		)	(11.5		)	4.2			(1.2		)	3.0
Other changes in assets and liabilities:
Other	32.0			4.6			36.6			(14.0		)	2.8			(11.2		)

WPL	2014							2013
Income Statements			Effect of Change in							Effect of Change in
	Originally		Method of Calculating			As		Originally		Method of Calculating			As
	Reported		Income Taxes			Adjusted		Reported		Income Taxes			Adjusted
Income taxes		$85.6		($0.3	)		$85.3		$87.2		($1.6	)		$85.6
Net income	180.8		0.3			181.1		177.5		1.6			179.1
Earnings available for common stock	180.1		0.3			180.4		175.9		1.6			177.5

WPL			Effect of New			Effect of Change in
Balance Sheets	Originally		Accounting			Method of Calculating			As
December 31, 2014	Reported		Standard			Income Taxes			Adjusted
Deferred tax assets		$37.5		$—			$0.2			$37.7
Total current assets	457.2		—			0.2			457.4
Deferred charges and other	29.7		(10.8		)	—			18.9
Total other assets	426.1		(10.8		)	—			415.3
Total assets	5,128.2		(10.8		)	0.2			5,117.6
Long-term debt, net (excluding current portion)	1,543.3		(10.8		)	—			1,532.5
Deferred tax liabilities	970.0		—			(2.9		)	967.1
Total other liabilities	1,562.3		—			(2.9		)	1,559.4
Retained earnings	678.6		—			3.1			681.7
Total WPL common equity	1,703.8		—			3.1			1,706.9
Total equity	1,712.3		—			3.1			1,715.4
Total liabilities and equity	5,128.2		(10.8		)	0.2			5,117.6
January 1, 2014
Retained earnings	617.2		—			5.0			622.2
January 1, 2013
Retained earnings	557.6		—			8.3			565.9

WPL	2014									2013
Cash Flows				Effect of Change in									Effect of Change in
	Originally			Method of Calculating			As			Originally			Method of Calculating			As
	Reported			Income Taxes			Adjusted			Reported			Income Taxes			Adjusted
Cash flows from operating activities:
Net income		$180.8			$0.3			$181.1			$177.5			$1.6			$179.1
Adjustments to reconcile net income to net cash flows from operating activities:
Deferred tax expense and investment tax credits	80.7			1.9			82.6			86.5			3.3			89.8
Other changes in assets and liabilities:
Other	(6.8		)	(2.2		)	(9.0		)	(16.7		)	(4.9		)	(21.6		)

The change in method of calculating the income tax provisions and related deferred tax assets and liabilities for IPL and WPL did not have a material impact on their income statements or cash flows statements for 2015. The following balance sheet line items for 2015 were affected by this change in method for IPL and WPL (in millions):

IPL	As Computed Under		As Reported Under
Balance Sheet as of December 31, 2015	Parent-company-down		Modified Separate		Effect of
	Approach		Return Approach		Change
Deferred tax liabilities		$1,346.7		$1,378.0		$31.3
Total other liabilities	2,094.5		2,125.8		31.3
Retained earnings	585.4		554.1		(31.3		)
Total IPL common equity	2,026.6		1,995.3		(31.3		)
Total equity	2,226.6		2,195.3		(31.3		)

WPL	As Computed Under		As Reported Under
Balance Sheet as of December 31, 2015	Parent-company-down		Modified Separate		Effect of
	Approach		Return Approach		Change
Other current liabilities		$78.2		$79.5		$1.3
Total current liabilities	335.6		336.9		1.3
Deferred tax liabilities	1,010.8		1,005.4		(5.4		)
Total other liabilities	1,637.4		1,632.0		(5.4		)
Retained earnings	727.0		731.1		4.1
Total WPL common equity	1,752.2		1,756.3		4.1
Total equity	1,763.5		1,767.6		4.1

In addition, the following previously reported Selected Consolidated Quarterly Financial Data (Unaudited) for the three months ended were impacted as a result of the change in method of calculating the income tax provisions and related deferred tax assets and liabilities for IPL and WPL (in millions):

	March 31, 2015				June 30, 2015				September 30, 2015
	Originally		As		Originally		As		Originally		As
	Reported		Adjusted		Reported		Adjusted		Reported		Adjusted
IPL
Net income		$50.4		$50.1		$19.2		$19.0		$120.0		$119.1
Earnings available for common stock	47.8		47.5		16.7		16.5		117.4		116.5
WPL
Net income	44.8		45.1		39.5		39.7		67.9		68.4
Earnings available for common stock	44.6		44.9		39.0		39.2		67.5		68.0

	March 31, 2014				June 30, 2014				September 30, 2014				December 31, 2014
	Originally		As		Originally		As		Originally		As		Originally		As
	Reported		Adjusted		Reported		Adjusted		Reported		Adjusted		Reported		Adjusted
IPL
Net income		$46.0		$45.3		$20.9		$20.5		$105.1		$104.6		$22.6		$21.4
Earnings available for common stock	43.4		42.7		18.4		18.0		102.5		102.0		20.1		18.9
WPL
Net income	54.8		55.2		34.6		34.7		61.6		57.9		29.8		33.3
Earnings available for common stock	54.8		55.2		34.6		34.7		61.6		57.9		29.1		32.6

IPL [Member]

Schedule of Average Rates of Depreciation

The average rates of depreciation for electric, gas and other properties, consistent with current rate-making practices, were as follows:

	IPL			WPL
	2015	2014	2013	2015	2014	2013
Electric - generation	3.6%	3.6%	3.6%	3.2%	3.2%	3.3%
Electric - distribution	2.4%	2.5%	2.5%	2.7%	2.7%	2.7%
Electric - other	4.0%	4.0%	4.0%	4.5%	5.9%	5.0%
Gas	3.2%	3.3%	3.4%	2.5%	2.5%	2.5%
Other	3.9%	4.3%	4.7%	6.0%	6.0%	5.1%

Schedule of Allowance for Funds Used During Construction Rate

The AFUDC rates, computed in accordance with the prescribed regulatory formula, were as follows:

	2015	2014	2013
IPL (Marshalltown CWIP) (a)	7.9%	8.0%	—%
IPL (other CWIP)	7.7%	7.8%	8.2%
WPL (retail jurisdiction)	8.2%	8.2%	8.2%
WPL (wholesale jurisdiction)	7.9%	4.1%	4.5%

(a) In 2013, the IUB issued an order establishing rate-making principles for Marshalltown that requires a 10.3% return on common equity for the calculation of AFUDC related to the construction of such facility.

Schedule of New Accounting Standards and Changes in Accounting Principles

The following financial statement line items were affected by these changes (in millions):

Alliant Energy	Originally		Effect of New			As
Balance Sheet as of December 31, 2014	Reported		Accounting Standard			Adjusted
Deferred charges and other		$43.9		($22.4	)		$21.5
Total other assets	1,759.5		(22.4		)	1,737.1
Total assets	12,085.9		(22.4		)	12,063.5
Long-term debt, net (excluding current portion)	3,606.7		(22.4		)	3,584.3
Total liabilities and equity	12,085.9		(22.4		)	12,063.5

IPL	2014									2013
Income Statements				Effect of Change in									Effect of Change in
	Originally			Method of Calculating			As			Originally			Method of Calculating			As
	Reported			Income Taxes			Adjusted			Reported			Income Taxes			Adjusted
Income tax benefit		($51.7	)		$2.8			($48.9	)		($37.9	)		$1.6			($36.3	)
Net income	194.6			(2.8		)	191.8			189.9			(1.6		)	188.3
Earnings available for common stock	184.4			(2.8		)	181.6			173.6			(1.6		)	172.0

IPL			Effect of New			Effect of Change in
Balance Sheets	Originally		Accounting			Method of Calculating			As
December 31, 2014	Reported		Standard			Income Taxes			Adjusted
Deferred tax assets		$104.9		$—			($0.9	)		$104.0
Total current assets	556.1		—			(0.9		)	555.2
Deferred charges and other	12.7		(10.7		)	—			2.0
Total other assets	1,331.9		(10.7		)	—			1,321.2
Total assets	6,461.8		(10.7		)	(0.9		)	6,450.2
Long-term debt, net (excluding current portion)	1,618.7		(10.7		)	—			1,608.0
Deferred tax liabilities	1,341.4		—			28.9			1,370.3
Total other liabilities	2,123.1		—			28.9			2,152.0
Retained earnings	537.9		—			(29.8		)	508.1
Total IPL common equity	1,814.1		—			(29.8		)	1,784.3
Total equity	2,014.1		—			(29.8		)	1,984.3
Total liabilities and equity	6,461.8		(10.7		)	(0.9		)	6,450.2
January 1, 2014
Retained earnings	493.5		—			(31.6		)	461.9
January 1, 2013
Retained earnings	448.0		—			(32.8		)	415.2

IPL	2014									2013
Cash Flows				Effect of Change in									Effect of Change in
	Originally			Method of Calculating			As			Originally			Method of Calculating			As
	Reported			Income Taxes			Adjusted			Reported			Income Taxes			Adjusted
Cash flows from operating activities:
Net income		$194.6			($2.8	)		$191.8			$189.9			($1.6	)		$188.3
Adjustments to reconcile net income to net cash flows from operating activities:
Deferred tax expense (benefit) and investment tax credits	(9.7		)	(1.8		)	(11.5		)	4.2			(1.2		)	3.0
Other changes in assets and liabilities:
Other	32.0			4.6			36.6			(14.0		)	2.8			(11.2		)

WPL	2014							2013
Income Statements			Effect of Change in							Effect of Change in
	Originally		Method of Calculating			As		Originally		Method of Calculating			As
	Reported		Income Taxes			Adjusted		Reported		Income Taxes			Adjusted
Income taxes		$85.6		($0.3	)		$85.3		$87.2		($1.6	)		$85.6
Net income	180.8		0.3			181.1		177.5		1.6			179.1
Earnings available for common stock	180.1		0.3			180.4		175.9		1.6			177.5

WPL			Effect of New			Effect of Change in
Balance Sheets	Originally		Accounting			Method of Calculating			As
December 31, 2014	Reported		Standard			Income Taxes			Adjusted
Deferred tax assets		$37.5		$—			$0.2			$37.7
Total current assets	457.2		—			0.2			457.4
Deferred charges and other	29.7		(10.8		)	—			18.9
Total other assets	426.1		(10.8		)	—			415.3
Total assets	5,128.2		(10.8		)	0.2			5,117.6
Long-term debt, net (excluding current portion)	1,543.3		(10.8		)	—			1,532.5
Deferred tax liabilities	970.0		—			(2.9		)	967.1
Total other liabilities	1,562.3		—			(2.9		)	1,559.4
Retained earnings	678.6		—			3.1			681.7
Total WPL common equity	1,703.8		—			3.1			1,706.9
Total equity	1,712.3		—			3.1			1,715.4
Total liabilities and equity	5,128.2		(10.8		)	0.2			5,117.6
January 1, 2014
Retained earnings	617.2		—			5.0			622.2
January 1, 2013
Retained earnings	557.6		—			8.3			565.9

WPL	2014									2013
Cash Flows				Effect of Change in									Effect of Change in
	Originally			Method of Calculating			As			Originally			Method of Calculating			As
	Reported			Income Taxes			Adjusted			Reported			Income Taxes			Adjusted
Cash flows from operating activities:
Net income		$180.8			$0.3			$181.1			$177.5			$1.6			$179.1
Adjustments to reconcile net income to net cash flows from operating activities:
Deferred tax expense and investment tax credits	80.7			1.9			82.6			86.5			3.3			89.8
Other changes in assets and liabilities:
Other	(6.8		)	(2.2		)	(9.0		)	(16.7		)	(4.9		)	(21.6		)

The change in method of calculating the income tax provisions and related deferred tax assets and liabilities for IPL and WPL did not have a material impact on their income statements or cash flows statements for 2015. The following balance sheet line items for 2015 were affected by this change in method for IPL and WPL (in millions):

IPL	As Computed Under		As Reported Under
Balance Sheet as of December 31, 2015	Parent-company-down		Modified Separate		Effect of
	Approach		Return Approach		Change
Deferred tax liabilities		$1,346.7		$1,378.0		$31.3
Total other liabilities	2,094.5		2,125.8		31.3
Retained earnings	585.4		554.1		(31.3		)
Total IPL common equity	2,026.6		1,995.3		(31.3		)
Total equity	2,226.6		2,195.3		(31.3		)

WPL	As Computed Under		As Reported Under
Balance Sheet as of December 31, 2015	Parent-company-down		Modified Separate		Effect of
	Approach		Return Approach		Change
Other current liabilities		$78.2		$79.5		$1.3
Total current liabilities	335.6		336.9		1.3
Deferred tax liabilities	1,010.8		1,005.4		(5.4		)
Total other liabilities	1,637.4		1,632.0		(5.4		)
Retained earnings	727.0		731.1		4.1
Total WPL common equity	1,752.2		1,756.3		4.1
Total equity	1,763.5		1,767.6		4.1

In addition, the following previously reported Selected Consolidated Quarterly Financial Data (Unaudited) for the three months ended were impacted as a result of the change in method of calculating the income tax provisions and related deferred tax assets and liabilities for IPL and WPL (in millions):

	March 31, 2015				June 30, 2015				September 30, 2015
	Originally		As		Originally		As		Originally		As
	Reported		Adjusted		Reported		Adjusted		Reported		Adjusted
IPL
Net income		$50.4		$50.1		$19.2		$19.0		$120.0		$119.1
Earnings available for common stock	47.8		47.5		16.7		16.5		117.4		116.5
WPL
Net income	44.8		45.1		39.5		39.7		67.9		68.4
Earnings available for common stock	44.6		44.9		39.0		39.2		67.5		68.0

	March 31, 2014				June 30, 2014				September 30, 2014				December 31, 2014
	Originally		As		Originally		As		Originally		As		Originally		As
	Reported		Adjusted		Reported		Adjusted		Reported		Adjusted		Reported		Adjusted
IPL
Net income		$46.0		$45.3		$20.9		$20.5		$105.1		$104.6		$22.6		$21.4
Earnings available for common stock	43.4		42.7		18.4		18.0		102.5		102.0		20.1		18.9
WPL
Net income	54.8		55.2		34.6		34.7		61.6		57.9		29.8		33.3
Earnings available for common stock	54.8		55.2		34.6		34.7		61.6		57.9		29.1		32.6

WPL [Member]

Schedule of Average Rates of Depreciation

The average rates of depreciation for electric, gas and other properties, consistent with current rate-making practices, were as follows:

	IPL			WPL
	2015	2014	2013	2015	2014	2013
Electric - generation	3.6%	3.6%	3.6%	3.2%	3.2%	3.3%
Electric - distribution	2.4%	2.5%	2.5%	2.7%	2.7%	2.7%
Electric - other	4.0%	4.0%	4.0%	4.5%	5.9%	5.0%
Gas	3.2%	3.3%	3.4%	2.5%	2.5%	2.5%
Other	3.9%	4.3%	4.7%	6.0%	6.0%	5.1%

Schedule of Allowance for Funds Used During Construction Rate

The AFUDC rates, computed in accordance with the prescribed regulatory formula, were as follows:

	2015	2014	2013
IPL (Marshalltown CWIP) (a)	7.9%	8.0%	—%
IPL (other CWIP)	7.7%	7.8%	8.2%
WPL (retail jurisdiction)	8.2%	8.2%	8.2%
WPL (wholesale jurisdiction)	7.9%	4.1%	4.5%

(a) In 2013, the IUB issued an order establishing rate-making principles for Marshalltown that requires a 10.3% return on common equity for the calculation of AFUDC related to the construction of such facility.

Schedule of New Accounting Standards and Changes in Accounting Principles

The following financial statement line items were affected by these changes (in millions):

Alliant Energy	Originally		Effect of New			As
Balance Sheet as of December 31, 2014	Reported		Accounting Standard			Adjusted
Deferred charges and other		$43.9		($22.4	)		$21.5
Total other assets	1,759.5		(22.4		)	1,737.1
Total assets	12,085.9		(22.4		)	12,063.5
Long-term debt, net (excluding current portion)	3,606.7		(22.4		)	3,584.3
Total liabilities and equity	12,085.9		(22.4		)	12,063.5

IPL	2014									2013
Income Statements				Effect of Change in									Effect of Change in
	Originally			Method of Calculating			As			Originally			Method of Calculating			As
	Reported			Income Taxes			Adjusted			Reported			Income Taxes			Adjusted
Income tax benefit		($51.7	)		$2.8			($48.9	)		($37.9	)		$1.6			($36.3	)
Net income	194.6			(2.8		)	191.8			189.9			(1.6		)	188.3
Earnings available for common stock	184.4			(2.8		)	181.6			173.6			(1.6		)	172.0

IPL			Effect of New			Effect of Change in
Balance Sheets	Originally		Accounting			Method of Calculating			As
December 31, 2014	Reported		Standard			Income Taxes			Adjusted
Deferred tax assets		$104.9		$—			($0.9	)		$104.0
Total current assets	556.1		—			(0.9		)	555.2
Deferred charges and other	12.7		(10.7		)	—			2.0
Total other assets	1,331.9		(10.7		)	—			1,321.2
Total assets	6,461.8		(10.7		)	(0.9		)	6,450.2
Long-term debt, net (excluding current portion)	1,618.7		(10.7		)	—			1,608.0
Deferred tax liabilities	1,341.4		—			28.9			1,370.3
Total other liabilities	2,123.1		—			28.9			2,152.0
Retained earnings	537.9		—			(29.8		)	508.1
Total IPL common equity	1,814.1		—			(29.8		)	1,784.3
Total equity	2,014.1		—			(29.8		)	1,984.3
Total liabilities and equity	6,461.8		(10.7		)	(0.9		)	6,450.2
January 1, 2014
Retained earnings	493.5		—			(31.6		)	461.9
January 1, 2013
Retained earnings	448.0		—			(32.8		)	415.2

IPL	2014									2013
Cash Flows				Effect of Change in									Effect of Change in
	Originally			Method of Calculating			As			Originally			Method of Calculating			As
	Reported			Income Taxes			Adjusted			Reported			Income Taxes			Adjusted
Cash flows from operating activities:
Net income		$194.6			($2.8	)		$191.8			$189.9			($1.6	)		$188.3
Adjustments to reconcile net income to net cash flows from operating activities:
Deferred tax expense (benefit) and investment tax credits	(9.7		)	(1.8		)	(11.5		)	4.2			(1.2		)	3.0
Other changes in assets and liabilities:
Other	32.0			4.6			36.6			(14.0		)	2.8			(11.2		)

WPL	2014							2013
Income Statements			Effect of Change in							Effect of Change in
	Originally		Method of Calculating			As		Originally		Method of Calculating			As
	Reported		Income Taxes			Adjusted		Reported		Income Taxes			Adjusted
Income taxes		$85.6		($0.3	)		$85.3		$87.2		($1.6	)		$85.6
Net income	180.8		0.3			181.1		177.5		1.6			179.1
Earnings available for common stock	180.1		0.3			180.4		175.9		1.6			177.5

WPL			Effect of New			Effect of Change in
Balance Sheets	Originally		Accounting			Method of Calculating			As
December 31, 2014	Reported		Standard			Income Taxes			Adjusted
Deferred tax assets		$37.5		$—			$0.2			$37.7
Total current assets	457.2		—			0.2			457.4
Deferred charges and other	29.7		(10.8		)	—			18.9
Total other assets	426.1		(10.8		)	—			415.3
Total assets	5,128.2		(10.8		)	0.2			5,117.6
Long-term debt, net (excluding current portion)	1,543.3		(10.8		)	—			1,532.5
Deferred tax liabilities	970.0		—			(2.9		)	967.1
Total other liabilities	1,562.3		—			(2.9		)	1,559.4
Retained earnings	678.6		—			3.1			681.7
Total WPL common equity	1,703.8		—			3.1			1,706.9
Total equity	1,712.3		—			3.1			1,715.4
Total liabilities and equity	5,128.2		(10.8		)	0.2			5,117.6
January 1, 2014
Retained earnings	617.2		—			5.0			622.2
January 1, 2013
Retained earnings	557.6		—			8.3			565.9

WPL	2014									2013
Cash Flows				Effect of Change in									Effect of Change in
	Originally			Method of Calculating			As			Originally			Method of Calculating			As
	Reported			Income Taxes			Adjusted			Reported			Income Taxes			Adjusted
Cash flows from operating activities:
Net income		$180.8			$0.3			$181.1			$177.5			$1.6			$179.1
Adjustments to reconcile net income to net cash flows from operating activities:
Deferred tax expense and investment tax credits	80.7			1.9			82.6			86.5			3.3			89.8
Other changes in assets and liabilities:
Other	(6.8		)	(2.2		)	(9.0		)	(16.7		)	(4.9		)	(21.6		)

The change in method of calculating the income tax provisions and related deferred tax assets and liabilities for IPL and WPL did not have a material impact on their income statements or cash flows statements for 2015. The following balance sheet line items for 2015 were affected by this change in method for IPL and WPL (in millions):

IPL	As Computed Under		As Reported Under
Balance Sheet as of December 31, 2015	Parent-company-down		Modified Separate		Effect of
	Approach		Return Approach		Change
Deferred tax liabilities		$1,346.7		$1,378.0		$31.3
Total other liabilities	2,094.5		2,125.8		31.3
Retained earnings	585.4		554.1		(31.3		)
Total IPL common equity	2,026.6		1,995.3		(31.3		)
Total equity	2,226.6		2,195.3		(31.3		)

WPL	As Computed Under		As Reported Under
Balance Sheet as of December 31, 2015	Parent-company-down		Modified Separate		Effect of
	Approach		Return Approach		Change
Other current liabilities		$78.2		$79.5		$1.3
Total current liabilities	335.6		336.9		1.3
Deferred tax liabilities	1,010.8		1,005.4		(5.4		)
Total other liabilities	1,637.4		1,632.0		(5.4		)
Retained earnings	727.0		731.1		4.1
Total WPL common equity	1,752.2		1,756.3		4.1
Total equity	1,763.5		1,767.6		4.1

In addition, the following previously reported Selected Consolidated Quarterly Financial Data (Unaudited) for the three months ended were impacted as a result of the change in method of calculating the income tax provisions and related deferred tax assets and liabilities for IPL and WPL (in millions):

	March 31, 2015				June 30, 2015				September 30, 2015
	Originally		As		Originally		As		Originally		As
	Reported		Adjusted		Reported		Adjusted		Reported		Adjusted
IPL
Net income		$50.4		$50.1		$19.2		$19.0		$120.0		$119.1
Earnings available for common stock	47.8		47.5		16.7		16.5		117.4		116.5
WPL
Net income	44.8		45.1		39.5		39.7		67.9		68.4
Earnings available for common stock	44.6		44.9		39.0		39.2		67.5		68.0

	March 31, 2014				June 30, 2014				September 30, 2014				December 31, 2014
	Originally		As		Originally		As		Originally		As		Originally		As
	Reported		Adjusted		Reported		Adjusted		Reported		Adjusted		Reported		Adjusted
IPL
Net income		$46.0		$45.3		$20.9		$20.5		$105.1		$104.6		$22.6		$21.4
Earnings available for common stock	43.4		42.7		18.4		18.0		102.5		102.0		20.1		18.9
WPL
Net income	54.8		55.2		34.6		34.7		61.6		57.9		29.8		33.3
Earnings available for common stock	54.8		55.2		34.6		34.7		61.6		57.9		29.1		32.6