XML 52 R31.htm IDEA: XBRL DOCUMENT v3.10.0.1
Fair Value Measurements (Tables)
 9 Months Ended
Sep. 30, 2018
Statement [Line Items]  
Fair Value Measurements
Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):
Alliant Energy
September 30, 2018
 
December 31, 2017
 
 
 
Fair Value
 
 
 
Fair Value
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Amount
 
1
 
2
 
3
 
Total
 
Amount
 
1
 
2
 
3
 
Total
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Money market fund investments

$228.0

 

$228.0

 

$—

 

$—

 

$228.0

 

$—

 

$—

 

$—

 

$—

 

$—

Derivatives
48.0

 
—

 
16.5

 
31.5

 
48.0

 
25.1

 
—

 
4.1

 
21.0

 
25.1

Deferred proceeds
243.7

 
—

 
—

 
243.7

 
243.7

 
222.1

 
—

 
—

 
222.1

 
222.1

Liabilities and equity:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives
22.0

 
—

 
14.7

 
7.3

 
22.0

 
41.7

 
—

 
8.5

 
33.2

 
41.7

Long-term debt (incl. current maturities)
5,754.3

 
—

 
6,057.8

 
2.5

 
6,060.3

 
4,866.3

 
—

 
5,444.6

 
2.9

 
5,447.5

Cumulative preferred stock of IPL
200.0

 
200.0

 
—

 
—

 
200.0

 
200.0

 
203.8

 
—

 
—

 
203.8

IPL
September 30, 2018
 
December 31, 2017
 
 
 
Fair Value
 
 
 
Fair Value
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Amount
 
1
 
2
 
3
 
Total
 
Amount
 
1
 
2
 
3
 
Total
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Money market fund investments

$228.0

 

$228.0

 

$—

 

$—

 

$228.0

 

$—

 

$—

 

$—

 

$—

 

$—

Derivatives
29.1

 
—

 
6.7

 
22.4

 
29.1

 
17.1

 
—

 
2.0

 
15.1

 
17.1

Deferred proceeds
243.7

 
—

 
—

 
243.7

 
243.7

 
222.1

 
—

 
—

 
222.1

 
222.1

Liabilities and equity:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives
9.7

 
—

 
5.5

 
4.2

 
9.7

 
19.4

 
—

 
2.9

 
16.5

 
19.4

Long-term debt (incl. current maturities)
2,801.8

 
—

 
2,916.2

 
—

 
2,916.2

 
2,406.0

 
—

 
2,665.7

 
—

 
2,665.7

Cumulative preferred stock
200.0

 
200.0

 
—

 
—

 
200.0

 
200.0

 
203.8

 
—

 
—

 
203.8

WPL
September 30, 2018
 
December 31, 2017
 
 
 
Fair Value
 
 
 
Fair Value
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Amount
 
1
 
2
 
3
 
Total
 
Amount
 
1
 
2
 
3
 
Total
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives

$18.9

 

$—

 

$9.8

 

$9.1

 

$18.9

 

$8.0

 

$—

 

$2.1

 

$5.9

 

$8.0

Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives
12.3

 
—

 
9.2

 
3.1

 
12.3

 
22.3

 
—

 
5.6

 
16.7

 
22.3

Long-term debt (incl. current maturities)
1,834.5

 
—

 
2,020.9

 
—

 
2,020.9

 
1,833.4

 
—

 
2,147.9

 
—

 
2,147.9
Fair Value Measurements Using Significant Unobservable Inputs
Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):
Alliant Energy
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Three Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, July 1

($10.7
)
 

$9.2

 

$208.3

 

$170.0

Total net gains (losses) included in changes in net assets (realized/unrealized)
25.7

 
(4.3
)
 
—

 
—

Transfers out of Level 3
15.6

 
—

 
—

 
—

Sales
(0.2
)
 
(0.1
)
 
—

 
—

Settlements (a)
(6.2
)
 
(8.5
)
 
35.4

 
(54.7
)
Ending balance, September 30

$24.2

 

($3.7
)
 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$26.1

 

($4.2
)
 

$—

 

$—

Alliant Energy
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Nine Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, January 1

($12.2
)
 

$8.7

 

$222.1

 

$211.1

Total net gains (losses) included in changes in net assets (realized/unrealized)
15.7

 
(31.3
)
 
—

 
—

Transfers out of Level 3
15.6

 
12.2

 
—

 
—

Purchases
26.7

 
28.3

 
—

 
—

Sales
(0.2
)
 
(0.3
)
 
—

 
—

Settlements (a)
(21.4
)
 
(21.3
)
 
21.6

 
(95.8
)
Ending balance, September 30

$24.2

 

($3.7
)
 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$16.5

 

($29.4
)
 

$—

 

$—

IPL
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Three Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, July 1

($4.1
)
 

$17.1

 

$208.3

 

$170.0

Total net gains (losses) included in changes in net assets (realized/unrealized)
16.8

 
(4.4
)
 
—

 
—

Transfers out of Level 3
10.5

 
—

 
—

 
—

Sales
(0.1
)
 
(0.1
)
 
—

 
—

Settlements (a)
(4.9
)
 
(7.3
)
 
35.4

 
(54.7
)
Ending balance, September 30

$18.2

 

$5.3

 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$16.8

 

($4.5
)
 

$—

 

$—

IPL
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Nine Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, January 1

($1.4
)
 

$10.1

 

$222.1

 

$211.1

Total net gains (losses) included in changes in net assets (realized/unrealized)
7.6

 
(13.9
)
 
—

 
—

Transfers out of Level 3
10.5

 
3.1

 
—

 
—

Purchases
19.3

 
24.6

 
—

 
—

Sales
(0.1
)
 
(0.2
)
 
—

 
—

Settlements (a)
(17.7
)
 
(18.4
)
 
21.6

 
(95.8
)
Ending balance, September 30

$18.2

 

$5.3

 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$7.9

 

($12.6
)
 

$—

 

$—

WPL
Commodity Contract Derivative
 
Assets and (Liabilities), net
Three Months Ended September 30
2018
 
2017
Beginning balance, July 1

($6.6
)
 

($7.9
)
Total net gains included in changes in net assets (realized/unrealized)
8.9

 
0.1

Transfers out of Level 3
5.1

 
—

Sales
(0.1
)
 
—

Settlements
(1.3
)
 
(1.2
)
Ending balance, September 30

$6.0

 

($9.0
)
The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30

$9.3

 

$0.3

WPL
Commodity Contract Derivative
 
Assets and (Liabilities), net
Nine Months Ended September 30
2018
 
2017
Beginning balance, January 1

($10.8
)
 

($1.4
)
Total net gains (losses) included in changes in net assets (realized/unrealized)
8.1

 
(17.4
)
Transfers out of Level 3
5.1

 
9.1

Purchases
7.4

 
3.7

Sales
(0.1
)
 
(0.1
)
Settlements
(3.7
)
 
(2.9
)
Ending balance, September 30

$6.0

 

($9.0
)
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$8.6

 

($16.8
)

(a)
Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold.
Fair Value Of Net Derivative Assets (Liabilities)
The fair value of electric, natural gas, coal and diesel fuel commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions):
 
Alliant Energy
 
IPL
 
WPL
 
Excluding FTRs
 
FTRs
 
Excluding FTRs
 
FTRs
 
Excluding FTRs
 
FTRs
September 30, 2018

$7.9

 

$16.3

 

$5.4

 

$12.8

 

$2.5

 

$3.5

December 31, 2017
(23.5
)
 
11.3

 
(11.5
)
 
10.1

 
(12.0
)
 
1.2
IPL [Member]  
Statement [Line Items]  
Fair Value Measurements
Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):
Alliant Energy
September 30, 2018
 
December 31, 2017
 
 
 
Fair Value
 
 
 
Fair Value
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Amount
 
1
 
2
 
3
 
Total
 
Amount
 
1
 
2
 
3
 
Total
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Money market fund investments

$228.0

 

$228.0

 

$—

 

$—

 

$228.0

 

$—

 

$—

 

$—

 

$—

 

$—

Derivatives
48.0

 
—

 
16.5

 
31.5

 
48.0

 
25.1

 
—

 
4.1

 
21.0

 
25.1

Deferred proceeds
243.7

 
—

 
—

 
243.7

 
243.7

 
222.1

 
—

 
—

 
222.1

 
222.1

Liabilities and equity:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives
22.0

 
—

 
14.7

 
7.3

 
22.0

 
41.7

 
—

 
8.5

 
33.2

 
41.7

Long-term debt (incl. current maturities)
5,754.3

 
—

 
6,057.8

 
2.5

 
6,060.3

 
4,866.3

 
—

 
5,444.6

 
2.9

 
5,447.5

Cumulative preferred stock of IPL
200.0

 
200.0

 
—

 
—

 
200.0

 
200.0

 
203.8

 
—

 
—

 
203.8

IPL
September 30, 2018
 
December 31, 2017
 
 
 
Fair Value
 
 
 
Fair Value
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Amount
 
1
 
2
 
3
 
Total
 
Amount
 
1
 
2
 
3
 
Total
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Money market fund investments

$228.0

 

$228.0

 

$—

 

$—

 

$228.0

 

$—

 

$—

 

$—

 

$—

 

$—

Derivatives
29.1

 
—

 
6.7

 
22.4

 
29.1

 
17.1

 
—

 
2.0

 
15.1

 
17.1

Deferred proceeds
243.7

 
—

 
—

 
243.7

 
243.7

 
222.1

 
—

 
—

 
222.1

 
222.1

Liabilities and equity:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives
9.7

 
—

 
5.5

 
4.2

 
9.7

 
19.4

 
—

 
2.9

 
16.5

 
19.4

Long-term debt (incl. current maturities)
2,801.8

 
—

 
2,916.2

 
—

 
2,916.2

 
2,406.0

 
—

 
2,665.7

 
—

 
2,665.7

Cumulative preferred stock
200.0

 
200.0

 
—

 
—

 
200.0

 
200.0

 
203.8

 
—

 
—

 
203.8

WPL
September 30, 2018
 
December 31, 2017
 
 
 
Fair Value
 
 
 
Fair Value
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Amount
 
1
 
2
 
3
 
Total
 
Amount
 
1
 
2
 
3
 
Total
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives

$18.9

 

$—

 

$9.8

 

$9.1

 

$18.9

 

$8.0

 

$—

 

$2.1

 

$5.9

 

$8.0

Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives
12.3

 
—

 
9.2

 
3.1

 
12.3

 
22.3

 
—

 
5.6

 
16.7

 
22.3

Long-term debt (incl. current maturities)
1,834.5

 
—

 
2,020.9

 
—

 
2,020.9

 
1,833.4

 
—

 
2,147.9

 
—

 
2,147.9
Fair Value Measurements Using Significant Unobservable Inputs
Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):
Alliant Energy
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Three Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, July 1

($10.7
)
 

$9.2

 

$208.3

 

$170.0

Total net gains (losses) included in changes in net assets (realized/unrealized)
25.7

 
(4.3
)
 
—

 
—

Transfers out of Level 3
15.6

 
—

 
—

 
—

Sales
(0.2
)
 
(0.1
)
 
—

 
—

Settlements (a)
(6.2
)
 
(8.5
)
 
35.4

 
(54.7
)
Ending balance, September 30

$24.2

 

($3.7
)
 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$26.1

 

($4.2
)
 

$—

 

$—

Alliant Energy
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Nine Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, January 1

($12.2
)
 

$8.7

 

$222.1

 

$211.1

Total net gains (losses) included in changes in net assets (realized/unrealized)
15.7

 
(31.3
)
 
—

 
—

Transfers out of Level 3
15.6

 
12.2

 
—

 
—

Purchases
26.7

 
28.3

 
—

 
—

Sales
(0.2
)
 
(0.3
)
 
—

 
—

Settlements (a)
(21.4
)
 
(21.3
)
 
21.6

 
(95.8
)
Ending balance, September 30

$24.2

 

($3.7
)
 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$16.5

 

($29.4
)
 

$—

 

$—

IPL
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Three Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, July 1

($4.1
)
 

$17.1

 

$208.3

 

$170.0

Total net gains (losses) included in changes in net assets (realized/unrealized)
16.8

 
(4.4
)
 
—

 
—

Transfers out of Level 3
10.5

 
—

 
—

 
—

Sales
(0.1
)
 
(0.1
)
 
—

 
—

Settlements (a)
(4.9
)
 
(7.3
)
 
35.4

 
(54.7
)
Ending balance, September 30

$18.2

 

$5.3

 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$16.8

 

($4.5
)
 

$—

 

$—

IPL
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Nine Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, January 1

($1.4
)
 

$10.1

 

$222.1

 

$211.1

Total net gains (losses) included in changes in net assets (realized/unrealized)
7.6

 
(13.9
)
 
—

 
—

Transfers out of Level 3
10.5

 
3.1

 
—

 
—

Purchases
19.3

 
24.6

 
—

 
—

Sales
(0.1
)
 
(0.2
)
 
—

 
—

Settlements (a)
(17.7
)
 
(18.4
)
 
21.6

 
(95.8
)
Ending balance, September 30

$18.2

 

$5.3

 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$7.9

 

($12.6
)
 

$—

 

$—

WPL
Commodity Contract Derivative
 
Assets and (Liabilities), net
Three Months Ended September 30
2018
 
2017
Beginning balance, July 1

($6.6
)
 

($7.9
)
Total net gains included in changes in net assets (realized/unrealized)
8.9

 
0.1

Transfers out of Level 3
5.1

 
—

Sales
(0.1
)
 
—

Settlements
(1.3
)
 
(1.2
)
Ending balance, September 30

$6.0

 

($9.0
)
The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30

$9.3

 

$0.3

WPL
Commodity Contract Derivative
 
Assets and (Liabilities), net
Nine Months Ended September 30
2018
 
2017
Beginning balance, January 1

($10.8
)
 

($1.4
)
Total net gains (losses) included in changes in net assets (realized/unrealized)
8.1

 
(17.4
)
Transfers out of Level 3
5.1

 
9.1

Purchases
7.4

 
3.7

Sales
(0.1
)
 
(0.1
)
Settlements
(3.7
)
 
(2.9
)
Ending balance, September 30

$6.0

 

($9.0
)
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$8.6

 

($16.8
)

(a)
Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold.
Fair Value Of Net Derivative Assets (Liabilities)
The fair value of electric, natural gas, coal and diesel fuel commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions):
 
Alliant Energy
 
IPL
 
WPL
 
Excluding FTRs
 
FTRs
 
Excluding FTRs
 
FTRs
 
Excluding FTRs
 
FTRs
September 30, 2018

$7.9

 

$16.3

 

$5.4

 

$12.8

 

$2.5

 

$3.5

December 31, 2017
(23.5
)
 
11.3

 
(11.5
)
 
10.1

 
(12.0
)
 
1.2
WPL [Member]  
Statement [Line Items]  
Fair Value Measurements
Carrying amounts and related estimated fair values of other financial instruments were as follows (in millions):
Alliant Energy
September 30, 2018
 
December 31, 2017
 
 
 
Fair Value
 
 
 
Fair Value
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Amount
 
1
 
2
 
3
 
Total
 
Amount
 
1
 
2
 
3
 
Total
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Money market fund investments

$228.0

 

$228.0

 

$—

 

$—

 

$228.0

 

$—

 

$—

 

$—

 

$—

 

$—

Derivatives
48.0

 
—

 
16.5

 
31.5

 
48.0

 
25.1

 
—

 
4.1

 
21.0

 
25.1

Deferred proceeds
243.7

 
—

 
—

 
243.7

 
243.7

 
222.1

 
—

 
—

 
222.1

 
222.1

Liabilities and equity:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives
22.0

 
—

 
14.7

 
7.3

 
22.0

 
41.7

 
—

 
8.5

 
33.2

 
41.7

Long-term debt (incl. current maturities)
5,754.3

 
—

 
6,057.8

 
2.5

 
6,060.3

 
4,866.3

 
—

 
5,444.6

 
2.9

 
5,447.5

Cumulative preferred stock of IPL
200.0

 
200.0

 
—

 
—

 
200.0

 
200.0

 
203.8

 
—

 
—

 
203.8

IPL
September 30, 2018
 
December 31, 2017
 
 
 
Fair Value
 
 
 
Fair Value
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Amount
 
1
 
2
 
3
 
Total
 
Amount
 
1
 
2
 
3
 
Total
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Money market fund investments

$228.0

 

$228.0

 

$—

 

$—

 

$228.0

 

$—

 

$—

 

$—

 

$—

 

$—

Derivatives
29.1

 
—

 
6.7

 
22.4

 
29.1

 
17.1

 
—

 
2.0

 
15.1

 
17.1

Deferred proceeds
243.7

 
—

 
—

 
243.7

 
243.7

 
222.1

 
—

 
—

 
222.1

 
222.1

Liabilities and equity:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives
9.7

 
—

 
5.5

 
4.2

 
9.7

 
19.4

 
—

 
2.9

 
16.5

 
19.4

Long-term debt (incl. current maturities)
2,801.8

 
—

 
2,916.2

 
—

 
2,916.2

 
2,406.0

 
—

 
2,665.7

 
—

 
2,665.7

Cumulative preferred stock
200.0

 
200.0

 
—

 
—

 
200.0

 
200.0

 
203.8

 
—

 
—

 
203.8

WPL
September 30, 2018
 
December 31, 2017
 
 
 
Fair Value
 
 
 
Fair Value
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Carrying
 
Level
 
Level
 
Level
 
 
 
Amount
 
1
 
2
 
3
 
Total
 
Amount
 
1
 
2
 
3
 
Total
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives

$18.9

 

$—

 

$9.8

 

$9.1

 

$18.9

 

$8.0

 

$—

 

$2.1

 

$5.9

 

$8.0

Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Derivatives
12.3

 
—

 
9.2

 
3.1

 
12.3

 
22.3

 
—

 
5.6

 
16.7

 
22.3

Long-term debt (incl. current maturities)
1,834.5

 
—

 
2,020.9

 
—

 
2,020.9

 
1,833.4

 
—

 
2,147.9

 
—

 
2,147.9
Fair Value Measurements Using Significant Unobservable Inputs
Information for fair value measurements using significant unobservable inputs (Level 3 inputs) was as follows (in millions):
Alliant Energy
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Three Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, July 1

($10.7
)
 

$9.2

 

$208.3

 

$170.0

Total net gains (losses) included in changes in net assets (realized/unrealized)
25.7

 
(4.3
)
 
—

 
—

Transfers out of Level 3
15.6

 
—

 
—

 
—

Sales
(0.2
)
 
(0.1
)
 
—

 
—

Settlements (a)
(6.2
)
 
(8.5
)
 
35.4

 
(54.7
)
Ending balance, September 30

$24.2

 

($3.7
)
 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$26.1

 

($4.2
)
 

$—

 

$—

Alliant Energy
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Nine Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, January 1

($12.2
)
 

$8.7

 

$222.1

 

$211.1

Total net gains (losses) included in changes in net assets (realized/unrealized)
15.7

 
(31.3
)
 
—

 
—

Transfers out of Level 3
15.6

 
12.2

 
—

 
—

Purchases
26.7

 
28.3

 
—

 
—

Sales
(0.2
)
 
(0.3
)
 
—

 
—

Settlements (a)
(21.4
)
 
(21.3
)
 
21.6

 
(95.8
)
Ending balance, September 30

$24.2

 

($3.7
)
 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$16.5

 

($29.4
)
 

$—

 

$—

IPL
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Three Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, July 1

($4.1
)
 

$17.1

 

$208.3

 

$170.0

Total net gains (losses) included in changes in net assets (realized/unrealized)
16.8

 
(4.4
)
 
—

 
—

Transfers out of Level 3
10.5

 
—

 
—

 
—

Sales
(0.1
)
 
(0.1
)
 
—

 
—

Settlements (a)
(4.9
)
 
(7.3
)
 
35.4

 
(54.7
)
Ending balance, September 30

$18.2

 

$5.3

 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$16.8

 

($4.5
)
 

$—

 

$—

IPL
Commodity Contract Derivative
 
 
 
Assets and (Liabilities), net
 
Deferred Proceeds
Nine Months Ended September 30
2018
 
2017
 
2018
 
2017
Beginning balance, January 1

($1.4
)
 

$10.1

 

$222.1

 

$211.1

Total net gains (losses) included in changes in net assets (realized/unrealized)
7.6

 
(13.9
)
 
—

 
—

Transfers out of Level 3
10.5

 
3.1

 
—

 
—

Purchases
19.3

 
24.6

 
—

 
—

Sales
(0.1
)
 
(0.2
)
 
—

 
—

Settlements (a)
(17.7
)
 
(18.4
)
 
21.6

 
(95.8
)
Ending balance, September 30

$18.2

 

$5.3

 

$243.7

 

$115.3

The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$7.9

 

($12.6
)
 

$—

 

$—

WPL
Commodity Contract Derivative
 
Assets and (Liabilities), net
Three Months Ended September 30
2018
 
2017
Beginning balance, July 1

($6.6
)
 

($7.9
)
Total net gains included in changes in net assets (realized/unrealized)
8.9

 
0.1

Transfers out of Level 3
5.1

 
—

Sales
(0.1
)
 
—

Settlements
(1.3
)
 
(1.2
)
Ending balance, September 30

$6.0

 

($9.0
)
The amount of total net gains for the period included in changes in net assets attributable to the change in unrealized gains relating to assets and liabilities held at September 30

$9.3

 

$0.3

WPL
Commodity Contract Derivative
 
Assets and (Liabilities), net
Nine Months Ended September 30
2018
 
2017
Beginning balance, January 1

($10.8
)
 

($1.4
)
Total net gains (losses) included in changes in net assets (realized/unrealized)
8.1

 
(17.4
)
Transfers out of Level 3
5.1

 
9.1

Purchases
7.4

 
3.7

Sales
(0.1
)
 
(0.1
)
Settlements
(3.7
)
 
(2.9
)
Ending balance, September 30

$6.0

 

($9.0
)
The amount of total net gains (losses) for the period included in changes in net assets attributable to the change in unrealized gains (losses) relating to assets and liabilities held at September 30

$8.6

 

($16.8
)

(a)
Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold.
Fair Value Of Net Derivative Assets (Liabilities)
The fair value of electric, natural gas, coal and diesel fuel commodity contracts categorized as Level 3 was recognized as net derivative assets (liabilities) as follows (in millions):
 
Alliant Energy
 
IPL
 
WPL
 
Excluding FTRs
 
FTRs
 
Excluding FTRs
 
FTRs
 
Excluding FTRs
 
FTRs
September 30, 2018

$7.9

 

$16.3

 

$5.4

 

$12.8

 

$2.5

 

$3.5

December 31, 2017
(23.5
)
 
11.3

 
(11.5
)
 
10.1

 
(12.0
)
 
1.2