XML 36 R13.htm IDEA: XBRL DOCUMENT v3.7.0.1
Income Taxes
 6 Months Ended
Jun. 30, 2017
Income Taxes [Line Items]  
Income Taxes
INCOME TAXES
Income Tax Rates - The overall income tax rates shown in the following table were computed by dividing income tax expense (benefit) by income from continuing operations before income taxes.
 
Alliant Energy
 
IPL
 
WPL
Three Months Ended June 30
2017
 
2016
 
2017
 
2016
 
2017
 
2016
Statutory federal income tax rate
35.0
 %
 
35.0
 %
 
35.0
%
 
35.0
%
 
35.0
 %
 
35.0
 %
Effect of rate-making on property-related differences
(9.0
)
 
(4.9
)
 
(18.0
)
 
(8.8
)
 
(1.9
)
 
(1.0
)
IPL’s tax benefit riders
(7.8
)
 
(7.9
)
 
(18.6
)
 
(16.6
)
 
—

 
—

Production tax credits
(5.9
)
 
(5.7
)
 
(6.2
)
 
(5.3
)
 
(7.1
)
 
(6.3
)
Other items, net
5.7

 
0.7

 
6.5

 
(2.0
)
 
4.5

 
4.5

Overall income tax rate
18.0
%
 
17.2
%
 
(1.3
%)
 
2.3
%
 
30.5
%
 
32.2
%

 
Alliant Energy
 
IPL
 
WPL
Six Months Ended June 30
2017
 
2016
 
2017
 
2016
 
2017
 
2016
Statutory federal income tax rate
35.0
 %
 
35.0
 %
 
35.0
%
 
35.0
%
 
35.0
 %
 
35.0
 %
Effect of rate-making on property-related differences
(8.0
)
 
(5.9
)
 
(18.0
)
 
(12.5
)
 
(1.8
)
 
(0.9
)
IPL’s tax benefit riders
(7.8
)
 
(8.4
)
 
(19.0
)
 
(19.0
)
 
—

 
—

Production tax credits
(5.9
)
 
(6.0
)
 
(6.4
)
 
(6.1
)
 
(7.0
)
 
(6.4
)
Other items, net
3.1

 
2.8

 
3.1

 
2.6

 
4.5

 
4.7

Overall income tax rate
16.4
%
 
17.5
%
 
(5.3
%)
 
—
%
 
30.7
%
 
32.4
%


Deferred Tax Assets and Liabilities - For the six months ended June 30, 2017, Alliant Energy’s, IPL’s and WPL’s deferred tax liabilities increased $111.1 million, $75.1 million and $28.4 million, respectively. These increases were primarily due to property-related differences recorded during the six months ended June 30, 2017. Alliant Energy’s and IPL’s increases were partially offset by the generation of federal net operating losses recorded during the six months ended June 30, 2017, which are primarily due to the accelerated tax depreciation associated with Marshalltown.

Carryforwards - At June 30, 2017, carryforwards and expiration dates were estimated as follows (in millions):
 
Range of Expiration Dates
 
Alliant Energy
 
IPL
 
WPL
Federal net operating losses
2030-2037
 

$736

 

$412

 

$217

State net operating losses
2018-2037
 
707

 
14

 
2

Federal tax credits
2022-2037
 
292

 
108

 
123
IPL [Member]  
Income Taxes [Line Items]  
Income Taxes
INCOME TAXES
Income Tax Rates - The overall income tax rates shown in the following table were computed by dividing income tax expense (benefit) by income from continuing operations before income taxes.
 
Alliant Energy
 
IPL
 
WPL
Three Months Ended June 30
2017
 
2016
 
2017
 
2016
 
2017
 
2016
Statutory federal income tax rate
35.0
 %
 
35.0
 %
 
35.0
%
 
35.0
%
 
35.0
 %
 
35.0
 %
Effect of rate-making on property-related differences
(9.0
)
 
(4.9
)
 
(18.0
)
 
(8.8
)
 
(1.9
)
 
(1.0
)
IPL’s tax benefit riders
(7.8
)
 
(7.9
)
 
(18.6
)
 
(16.6
)
 
—

 
—

Production tax credits
(5.9
)
 
(5.7
)
 
(6.2
)
 
(5.3
)
 
(7.1
)
 
(6.3
)
Other items, net
5.7

 
0.7

 
6.5

 
(2.0
)
 
4.5

 
4.5

Overall income tax rate
18.0
%
 
17.2
%
 
(1.3
%)
 
2.3
%
 
30.5
%
 
32.2
%

 
Alliant Energy
 
IPL
 
WPL
Six Months Ended June 30
2017
 
2016
 
2017
 
2016
 
2017
 
2016
Statutory federal income tax rate
35.0
 %
 
35.0
 %
 
35.0
%
 
35.0
%
 
35.0
 %
 
35.0
 %
Effect of rate-making on property-related differences
(8.0
)
 
(5.9
)
 
(18.0
)
 
(12.5
)
 
(1.8
)
 
(0.9
)
IPL’s tax benefit riders
(7.8
)
 
(8.4
)
 
(19.0
)
 
(19.0
)
 
—

 
—

Production tax credits
(5.9
)
 
(6.0
)
 
(6.4
)
 
(6.1
)
 
(7.0
)
 
(6.4
)
Other items, net
3.1

 
2.8

 
3.1

 
2.6

 
4.5

 
4.7

Overall income tax rate
16.4
%
 
17.5
%
 
(5.3
%)
 
—
%
 
30.7
%
 
32.4
%


Deferred Tax Assets and Liabilities - For the six months ended June 30, 2017, Alliant Energy’s, IPL’s and WPL’s deferred tax liabilities increased $111.1 million, $75.1 million and $28.4 million, respectively. These increases were primarily due to property-related differences recorded during the six months ended June 30, 2017. Alliant Energy’s and IPL’s increases were partially offset by the generation of federal net operating losses recorded during the six months ended June 30, 2017, which are primarily due to the accelerated tax depreciation associated with Marshalltown.

Carryforwards - At June 30, 2017, carryforwards and expiration dates were estimated as follows (in millions):
 
Range of Expiration Dates
 
Alliant Energy
 
IPL
 
WPL
Federal net operating losses
2030-2037
 

$736

 

$412

 

$217

State net operating losses
2018-2037
 
707

 
14

 
2

Federal tax credits
2022-2037
 
292

 
108

 
123
WPL [Member]  
Income Taxes [Line Items]  
Income Taxes
INCOME TAXES
Income Tax Rates - The overall income tax rates shown in the following table were computed by dividing income tax expense (benefit) by income from continuing operations before income taxes.
 
Alliant Energy
 
IPL
 
WPL
Three Months Ended June 30
2017
 
2016
 
2017
 
2016
 
2017
 
2016
Statutory federal income tax rate
35.0
 %
 
35.0
 %
 
35.0
%
 
35.0
%
 
35.0
 %
 
35.0
 %
Effect of rate-making on property-related differences
(9.0
)
 
(4.9
)
 
(18.0
)
 
(8.8
)
 
(1.9
)
 
(1.0
)
IPL’s tax benefit riders
(7.8
)
 
(7.9
)
 
(18.6
)
 
(16.6
)
 
—

 
—

Production tax credits
(5.9
)
 
(5.7
)
 
(6.2
)
 
(5.3
)
 
(7.1
)
 
(6.3
)
Other items, net
5.7

 
0.7

 
6.5

 
(2.0
)
 
4.5

 
4.5

Overall income tax rate
18.0
%
 
17.2
%
 
(1.3
%)
 
2.3
%
 
30.5
%
 
32.2
%

 
Alliant Energy
 
IPL
 
WPL
Six Months Ended June 30
2017
 
2016
 
2017
 
2016
 
2017
 
2016
Statutory federal income tax rate
35.0
 %
 
35.0
 %
 
35.0
%
 
35.0
%
 
35.0
 %
 
35.0
 %
Effect of rate-making on property-related differences
(8.0
)
 
(5.9
)
 
(18.0
)
 
(12.5
)
 
(1.8
)
 
(0.9
)
IPL’s tax benefit riders
(7.8
)
 
(8.4
)
 
(19.0
)
 
(19.0
)
 
—

 
—

Production tax credits
(5.9
)
 
(6.0
)
 
(6.4
)
 
(6.1
)
 
(7.0
)
 
(6.4
)
Other items, net
3.1

 
2.8

 
3.1

 
2.6

 
4.5

 
4.7

Overall income tax rate
16.4
%
 
17.5
%
 
(5.3
%)
 
—
%
 
30.7
%
 
32.4
%


Deferred Tax Assets and Liabilities - For the six months ended June 30, 2017, Alliant Energy’s, IPL’s and WPL’s deferred tax liabilities increased $111.1 million, $75.1 million and $28.4 million, respectively. These increases were primarily due to property-related differences recorded during the six months ended June 30, 2017. Alliant Energy’s and IPL’s increases were partially offset by the generation of federal net operating losses recorded during the six months ended June 30, 2017, which are primarily due to the accelerated tax depreciation associated with Marshalltown.

Carryforwards - At June 30, 2017, carryforwards and expiration dates were estimated as follows (in millions):
 
Range of Expiration Dates
 
Alliant Energy
 
IPL
 
WPL
Federal net operating losses
2030-2037
 

$736

 

$412

 

$217

State net operating losses
2018-2037
 
707

 
14

 
2

Federal tax credits
2022-2037
 
292

 
108

 
123