Commitments And Contingencies (Tables)

6 Months Ended

Jun. 30, 2015

Commitments and Contingencies [Line Items]

Operating Expense Purchase Obligations

At June 30, 2015, minimum future commitments related to these operating expense purchase obligations were as follows (in millions):

	Alliant Energy		IPL		WPL
Purchased power (a):
DAEC (IPL)		$1,480		$1,480		$—
Other	202		1		201
	1,682		1,481		201
Natural gas	270		165		105
Coal (b)	279		114		165
SO2 emission allowances	22		22		—
Other (c)	24		17		7
		$2,277		$1,799		$478

(a) Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased.

(b) Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of June 30, 2015 regarding expected future usage, which is subject to change.

(c) Includes individual commitments incurred during the normal course of business that exceeded $1 million at June 30, 2015.

MGP Site Estimated Future Costs And Recorded Liabilities

At June 30, 2015, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions):

	Alliant Energy				IPL				WPL
Range of estimated future costs		$12	-	$29		$10	-	$26		$2	-	$3
Current and non-current environmental liabilities	16				14				2

IPL [Member]

Commitments and Contingencies [Line Items]

Operating Expense Purchase Obligations

At June 30, 2015, minimum future commitments related to these operating expense purchase obligations were as follows (in millions):

	Alliant Energy		IPL		WPL
Purchased power (a):
DAEC (IPL)		$1,480		$1,480		$—
Other	202		1		201
	1,682		1,481		201
Natural gas	270		165		105
Coal (b)	279		114		165
SO2 emission allowances	22		22		—
Other (c)	24		17		7
		$2,277		$1,799		$478

(a) Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased.

(b) Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of June 30, 2015 regarding expected future usage, which is subject to change.

(c) Includes individual commitments incurred during the normal course of business that exceeded $1 million at June 30, 2015.

MGP Site Estimated Future Costs And Recorded Liabilities

At June 30, 2015, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions):

	Alliant Energy				IPL				WPL
Range of estimated future costs		$12	-	$29		$10	-	$26		$2	-	$3
Current and non-current environmental liabilities	16				14				2

WPL [Member]

Commitments and Contingencies [Line Items]

Operating Expense Purchase Obligations

At June 30, 2015, minimum future commitments related to these operating expense purchase obligations were as follows (in millions):

	Alliant Energy		IPL		WPL
Purchased power (a):
DAEC (IPL)		$1,480		$1,480		$—
Other	202		1		201
	1,682		1,481		201
Natural gas	270		165		105
Coal (b)	279		114		165
SO2 emission allowances	22		22		—
Other (c)	24		17		7
		$2,277		$1,799		$478

(a) Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased.

(b) Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of June 30, 2015 regarding expected future usage, which is subject to change.

(c) Includes individual commitments incurred during the normal course of business that exceeded $1 million at June 30, 2015.

MGP Site Estimated Future Costs And Recorded Liabilities

At June 30, 2015, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions):

	Alliant Energy				IPL				WPL
Range of estimated future costs		$12	-	$29		$10	-	$26		$2	-	$3
Current and non-current environmental liabilities	16				14				2